chore($shared-utils): fix typos in comments

Author: meteorlxy

packages/@vuepress/shared-utils/src/extractHeaders.ts

@@ -2,7 +2,7 @@ import LRU from 'lru-cache'
 import deeplyParseHeaders from './deeplyParseHeaders'
 
 /**
- * Extract heeaders from markdown source content.
+ * Extract headers from markdown source content.
  *
  * @param {string} content
  * @param {array} include

packages/@vuepress/shared-utils/src/moduleLoader.ts

@@ -1,4 +1,4 @@
-// Midified from https://github.com/vuejs/vue-cli/blob/dev/packages/@0vue/cli-shared-utils/lib/module.js
+// Modified from https://github.com/vuejs/vue-cli/blob/dev/packages/@0vue/cli-shared-utils/lib/module.js
 
 import semver from 'semver'
 import env from './env'

packages/@vuepress/shared-utils/src/moduleResolver.ts

@@ -191,7 +191,7 @@ class ModuleResolver {
     if (req.startsWith('@')) {
       const pkg = resolveScopePackage(req)
       if (pkg) {
-        // speicial handling for default org.
+        // special handling for default org.
         if (this.org && pkg.org === this.org) {
           shortcut = pkg.name.startsWith(`${this.type}-`)
             ? pkg.name.slice(this.typePrefixLength)

packages/@vuepress/shared-utils/src/parseHeaders.ts

@@ -8,8 +8,8 @@ import parseEmojis from './parseEmojis'
 // sidebar or title.
 //
 // But header's parsing in the markdown content is done by the markdown
-// loader based on markdown-it. markdown-it parser will will always keep
-// HTML in headers, so in VuePress, after being parsed by the markdiwn
+// loader based on markdown-it. markdown-it parser will always keep
+// HTML in headers, so in VuePress, after being parsed by the markdown
 // loader, the raw HTML in headers will finally be parsed by Vue-loader.
 // so that we can write HTML/Vue in the header. One exception is the HTML
 // wrapped by <code>(markdown token: '`') tag.

packages/@vuepress/shared-utils/src/slugify.ts

@@ -13,9 +13,9 @@ export = function slugify (str: string): string {
     .replace(rControl, '')
     // Replace special characters
     .replace(rSpecial, '-')
-    // Remove continous separators
+    // Remove continuous separators
     .replace(/\-{2,}/g, '-')
-    // Remove prefixing and trailing separtors
+    // Remove prefixing and trailing separators
     .replace(/^\-+|\-+$/g, '')
     // ensure it doesn't start with a number (#121)
     .replace(/^(\d)/, '_$1')