feat(link): Add input rule to insert links using markdown syntax

Fixes: #55

Code ideas taken from https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/assets/javascripts/content_editor/extensions/link.js

Signed-off-by: Jonas <jonas@freesources.org>

src/marks/Link.js

@@ -20,10 +20,27 @@
  *
  */
 
+import { markInputRule } from '@tiptap/core'
 import TipTapLink from '@tiptap/extension-link'
 import { domHref, parseHref } from './../helpers/links.js'
 import { linkClicking } from '../plugins/links.js'
 
+const extractHrefFromMatch = (match) => {
+	return { href: match.groups.href }
+}
+
+const extractHrefFromMarkdownLink = (match) => {
+	/**
+	 * Removes the last capture group from the match to satisfy
+	 * Tiptap markInputRule expectation of having the content as
+	 * the last capture group in the match.
+	 *
+	 * https://github.com/ueberdosis/tiptap/blob/%40tiptap/core%402.0.0-beta.75/packages/core/src/inputRules/markInputRule.ts#L11
+	 */
+	match.pop()
+	return extractHrefFromMatch(match)
+}
+
 const Link = TipTapLink.extend({
 
 	addOptions() {
@@ -66,6 +83,17 @@ const Link = TipTapLink.extend({
 		}, 0]
 	},
 
+	addInputRules() {
+		const linkInputRegex = /(?:^|\s)\[([\w|\s|-]+)\]\((?<href>.+?)\)$/gm
+		return [
+			markInputRule({
+				find: linkInputRegex,
+				type: this.type,
+				getAttributes: extractHrefFromMarkdownLink,
+			}),
+		]
+	},
+
 	addProseMirrorPlugins() {
 		const plugins = this.parent()
 			// remove upstream link click handle plugin