chore: Add Alex to lint documentation (#26354)

This Pull Request adds [Alex](https://alexjs.com/) to our documentation. It catches insensitive, inconsiderate writing. 

The original PR (https://github.com/vercel/next.js/pull/25821) is too large so I have decided to break it down into smaller PRs. This PR is the first part. Then I will continue to add the rest of the documentation in smaller PRs.

## More Information on Alex:
https://alexjs.com/
https://github.com/get-alex/alex

## Documentation / Examples

- [x] Make sure the linting passes

.alexignore

@@ -0,0 +1,4 @@
+CODE_OF_CONDUCT.md
+docs/
+errors/
+examples/

contributing.md

@@ -46,7 +46,7 @@ Running a specific test suite inside of the `test/integration` directory:
 yarn testonly --testPathPattern "production"
 ```
 
-Running just one test in the `production` test suite:
+Running one test in the `production` test suite:
 
 ```sh
 yarn testonly --testPathPattern "production" -t "should allow etag header support"

package.json

@@ -23,8 +23,9 @@
     "lint-typescript": "lerna run typescript",
     "lint-eslint": "eslint . --ext js,jsx,ts,tsx --max-warnings=0",
     "lint-no-typescript": "run-p prettier-check lint-eslint",
-    "lint": "run-p lint-typescript prettier-check lint-eslint",
+    "lint": "run-p lint-typescript prettier-check lint-eslint lint-language",
     "lint-fix": "yarn prettier-fix && eslint . --ext js,jsx,ts,tsx --fix --max-warnings=0",
+    "lint-language": "alex .",
     "prettier-check": "prettier --check .",
     "prettier-fix": "prettier --write .",
     "types": "lerna run types --stream",
@@ -56,6 +57,7 @@
     "@zeit/next-sass": "1.0.2-canary.2",
     "@zeit/next-typescript": "1.1.2-canary.0",
     "abort-controller": "3.0.0",
+    "alex": "9.1.0",
     "amphtml-validator": "1.0.33",
     "async-sema": "3.0.1",
     "babel-core": "7.0.0-bridge.0",

packages/create-next-app/README.md

@@ -1,6 +1,6 @@
 # Create Next App
 
-The easiest way to get started with Next.js is by using `create-next-app`. This simple CLI tool enables you to quickly start building a new Next.js application, with everything set up for you. You can create a new app using the default Next.js template, or by using one of the [official Next.js examples](https://github.com/vercel/next.js/tree/canary/examples). To get started, use the following command:
+The easiest way to get started with Next.js is by using `create-next-app`. This CLI tool enables you to quickly start building a new Next.js application, with everything set up for you. You can create a new app using the default Next.js template, or by using one of the [official Next.js examples](https://github.com/vercel/next.js/tree/canary/examples). To get started, use the following command:
 
 ```bash
 npx create-next-app

packages/next/compiled/webpack/bundle4.js

@@ -40466,7 +40466,7 @@ module.exports = isAccessorDescriptor;
 /***/ 1057:
 /***/ (function(module, __unused_webpack_exports, __webpack_require__) {
 
-var isBuffer = __webpack_require__(72195);
+var isBuffer = __webpack_require__(9848);
 var toString = Object.prototype.toString;
 
 /**
@@ -40584,6 +40584,34 @@ module.exports = function kindOf(val) {
 };
 
 
+/***/ }),
+
+/***/ 9848:
+/***/ (function(module) {
+
+/*!
+ * Determine if an object is a Buffer
+ *
+ * @author   Feross Aboukhadijeh <https://feross.org>
+ * @license  MIT
+ */
+
+// The _isBuffer check is for Safari 5-7 support, because it's missing
+// Object.prototype.constructor. Remove this eventually
+module.exports = function (obj) {
+  return obj != null && (isBuffer(obj) || isSlowBuffer(obj) || !!obj._isBuffer)
+}
+
+function isBuffer (obj) {
+  return !!obj.constructor && typeof obj.constructor.isBuffer === 'function' && obj.constructor.isBuffer(obj)
+}
+
+// For Node v0.10 support. Remove this eventually.
+function isSlowBuffer (obj) {
+  return typeof obj.readFloatLE === 'function' && typeof obj.slice === 'function' && isBuffer(obj.slice(0, 0))
+}
+
+
 /***/ }),
 
 /***/ 54963:
@@ -40652,7 +40680,7 @@ module.exports = isDataDescriptor;
 /***/ 31072:
 /***/ (function(module, __unused_webpack_exports, __webpack_require__) {
 
-var isBuffer = __webpack_require__(72195);
+var isBuffer = __webpack_require__(9848);
 var toString = Object.prototype.toString;
 
 /**
@@ -49527,12 +49555,40 @@ module.exports = function hasValue(val) {
 };
 
 
+/***/ }),
+
+/***/ 93293:
+/***/ (function(module) {
+
+/*!
+ * Determine if an object is a Buffer
+ *
+ * @author   Feross Aboukhadijeh <https://feross.org>
+ * @license  MIT
+ */
+
+// The _isBuffer check is for Safari 5-7 support, because it's missing
+// Object.prototype.constructor. Remove this eventually
+module.exports = function (obj) {
+  return obj != null && (isBuffer(obj) || isSlowBuffer(obj) || !!obj._isBuffer)
+}
+
+function isBuffer (obj) {
+  return !!obj.constructor && typeof obj.constructor.isBuffer === 'function' && obj.constructor.isBuffer(obj)
+}
+
+// For Node v0.10 support. Remove this eventually.
+function isSlowBuffer (obj) {
+  return typeof obj.readFloatLE === 'function' && typeof obj.slice === 'function' && isBuffer(obj.slice(0, 0))
+}
+
+
 /***/ }),
 
 /***/ 54329:
 /***/ (function(module, __unused_webpack_exports, __webpack_require__) {
 
-var isBuffer = __webpack_require__(72195);
+var isBuffer = __webpack_require__(93293);
 var toString = Object.prototype.toString;
 
 /**
@@ -49916,34 +49972,6 @@ function isBuffer(val) {
 }
 
 
-/***/ }),
-
-/***/ 72195:
-/***/ (function(module) {
-
-/*!
- * Determine if an object is a Buffer
- *
- * @author   Feross Aboukhadijeh <https://feross.org>
- * @license  MIT
- */
-
-// The _isBuffer check is for Safari 5-7 support, because it's missing
-// Object.prototype.constructor. Remove this eventually
-module.exports = function (obj) {
-  return obj != null && (isBuffer(obj) || isSlowBuffer(obj) || !!obj._isBuffer)
-}
-
-function isBuffer (obj) {
-  return !!obj.constructor && typeof obj.constructor.isBuffer === 'function' && obj.constructor.isBuffer(obj)
-}
-
-// For Node v0.10 support. Remove this eventually.
-function isSlowBuffer (obj) {
-  return typeof obj.readFloatLE === 'function' && typeof obj.slice === 'function' && isBuffer(obj.slice(0, 0))
-}
-
-
 /***/ }),
 
 /***/ 74194:
@@ -50579,7 +50607,7 @@ function escapeJsonPtr(str) {
 /***/ 48865:
 /***/ (function(module, __unused_webpack_exports, __webpack_require__) {
 
-var isBuffer = __webpack_require__(72195);
+var isBuffer = __webpack_require__(45408);
 var toString = Object.prototype.toString;
 
 /**
@@ -50697,6 +50725,34 @@ module.exports = function kindOf(val) {
 };
 
 
+/***/ }),
+
+/***/ 45408:
+/***/ (function(module) {
+
+/*!
+ * Determine if an object is a Buffer
+ *
+ * @author   Feross Aboukhadijeh <https://feross.org>
+ * @license  MIT
+ */
+
+// The _isBuffer check is for Safari 5-7 support, because it's missing
+// Object.prototype.constructor. Remove this eventually
+module.exports = function (obj) {
+  return obj != null && (isBuffer(obj) || isSlowBuffer(obj) || !!obj._isBuffer)
+}
+
+function isBuffer (obj) {
+  return !!obj.constructor && typeof obj.constructor.isBuffer === 'function' && obj.constructor.isBuffer(obj)
+}
+
+// For Node v0.10 support. Remove this eventually.
+function isSlowBuffer (obj) {
+  return typeof obj.readFloatLE === 'function' && typeof obj.slice === 'function' && isBuffer(obj.slice(0, 0))
+}
+
+
 /***/ }),
 
 /***/ 99736: