fix(eslint-plugin-next): Broken links in eslint output (vercel#32837)

This fixes broken links in the eslint output by removing the trailing full stop.
It also makes the formatting of (the output of) the various rules consistent.

## Documentation / Examples

- [x] Make sure the linting passes by running `yarn lint`

> I don't think this is a bug, nor a feature, nor is it really documentation. 
> It's just a small nuisance that I bumped into and felt compelled to fix.
> I went with documentation as that seems the closest match

## What does this pull request do?

The elslint output of `eslint-plugin-next` contains useful links to the documentation about the various rules.
Unfortunately, on most (but not all) rules, those links are immediately followed by a full stop (`.`).

The terminal (or any parser) has no way of knowing that the full stop is not part of the URL. 
So it includes it and clicking the link leads to a 404 on the nextjs.org website.
 
![eslint](https://user-images.githubusercontent.com/1708494/147452577-43ad4ce7-df75-4d48-ab78-70b9b8212b7e.png)

This PR fixes that by removing the full stop. 

## But a final full stop is better grammar

I considered alternatives (such as [a zero-width space character](https://en.wikipedia.org/wiki/Zero-width_space#Prohibited_in_URLs)) in case the final full stop was part of the style guide or something.

However, as I went through the eslint rules, I notices that the messages for various rules were formatted inconsistently. 
Some with final full stop, some without.

As such, I made the all consistent with this structure:

> [message]. See: [url]

I feel this is a better solution than using the zero-width space as these sort of invisible characters 
in code can be a red flag that something fishy is going on.

I submit this pull request in the hope it will be useful, and a positive contribution to a project I have a great deal of appreciation for.
That being said, I fully understand if people would consider this a non-issue.

Author: joostdecock

packages/eslint-plugin-next/lib/rules/google-font-display.js

@@ -48,7 +48,7 @@ module.exports = {
         if (message) {
           context.report({
             node,
-            message: `${message} See https://nextjs.org/docs/messages/google-font-display.`,
+            message: `${message} See: https://nextjs.org/docs/messages/google-font-display`,
           })
         }
       },

packages/eslint-plugin-next/lib/rules/google-font-preconnect.js

@@ -33,7 +33,7 @@ module.exports = {
         ) {
           context.report({
             node,
-            message: `Preconnect is missing. See https://nextjs.org/docs/messages/google-font-preconnect.`,
+            message: `Preconnect is missing. See: https://nextjs.org/docs/messages/google-font-preconnect`,
           })
         }
       },

packages/eslint-plugin-next/lib/rules/link-passhref.js

@@ -55,7 +55,7 @@ module.exports = {
               attributes.value('passHref') !== true
                 ? 'must be set to true'
                 : 'is missing'
-            }. See https://nextjs.org/docs/messages/link-passhref`,
+            }. See: https://nextjs.org/docs/messages/link-passhref`,
           })
         }
       },

packages/eslint-plugin-next/lib/rules/next-script-for-ga.js

@@ -9,7 +9,7 @@ const SUPPORTED_HTML_CONTENT_URLS = [
   'www.googletagmanager.com/gtm.js',
 ]
 const ERROR_MSG =
-  'Use the `next/script` component for loading third party scripts. See: https://nextjs.org/docs/messages/next-script-for-ga.'
+  'Use the `next/script` component for loading third party scripts. See: https://nextjs.org/docs/messages/next-script-for-ga'
 
 // Check if one of the items in the list is a substring of the passed string
 const containsStr = (str, strList) => {

packages/eslint-plugin-next/lib/rules/no-css-tags.js

@@ -26,7 +26,7 @@ module.exports = function (context) {
         context.report({
           node,
           message:
-            'Do not include stylesheets manually. See: https://nextjs.org/docs/messages/no-css-tags.',
+            'Do not include stylesheets manually. See: https://nextjs.org/docs/messages/no-css-tags',
         })
       }
     },

packages/eslint-plugin-next/lib/rules/no-document-import-in-page.js

@@ -29,7 +29,7 @@ module.exports = {
 
         context.report({
           node,
-          message: `next/document should not be imported outside of pages/_document.js. See https://nextjs.org/docs/messages/no-document-import-in-page.`,
+          message: `next/document should not be imported outside of pages/_document.js. See: https://nextjs.org/docs/messages/no-document-import-in-page`,
         })
       },
     }

packages/eslint-plugin-next/lib/rules/no-head-import-in-document.js

@@ -28,7 +28,7 @@ module.exports = {
         ) {
           context.report({
             node,
-            message: `next/head should not be imported in pages${document}. Import Head from next/document instead. See https://nextjs.org/docs/messages/no-head-import-in-document.`,
+            message: `next/head should not be imported in pages${document}. Import Head from next/document instead. See: https://nextjs.org/docs/messages/no-head-import-in-document`,
           })
         }
       },

packages/eslint-plugin-next/lib/rules/no-html-link-for-pages.js

@@ -125,7 +125,7 @@ module.exports = {
           if (url.test(normalizeURL(hrefPath))) {
             context.report({
               node,
-              message: `Do not use the HTML <a> tag to navigate to ${hrefPath}. Use Link from 'next/link' instead. See: https://nextjs.org/docs/messages/no-html-link-for-pages.`,
+              message: `Do not use the HTML <a> tag to navigate to ${hrefPath}. Use Link from 'next/link' instead. See: https://nextjs.org/docs/messages/no-html-link-for-pages`,
             })
           }
         })

packages/eslint-plugin-next/lib/rules/no-img-element.js

@@ -22,7 +22,7 @@ module.exports = {
 
         context.report({
           node,
-          message: `Do not use <img>. Use Image from 'next/image' instead. See https://nextjs.org/docs/messages/no-img-element.`,
+          message: `Do not use <img>. Use Image from 'next/image' instead. See: https://nextjs.org/docs/messages/no-img-element`,
         })
       },
     }

packages/eslint-plugin-next/lib/rules/no-page-custom-font.js

@@ -138,7 +138,7 @@ module.exports = {
 
         if (isGoogleFont) {
           const end =
-            'This is discouraged. See https://nextjs.org/docs/messages/no-page-custom-font.'
+            'This is discouraged. See: https://nextjs.org/docs/messages/no-page-custom-font'
 
           const message = is_Document
             ? `Rendering this <link /> not inline within <Head> of Document disables font optimization. ${end}`