Markdown editor (#92)

* Markdown editor

* use nocookie YT iframes

Co-authored-by: Emma Alexia Triphora <emma@modrinth.com>

* Fix line prefix-related Markdown editor bugs and add auto-lists

* Fix a couple codeblock issues

* address SearchFilter composition

* standardize code and patternize editor

* make editor typesafe

* adjust imports

* simplify key press handler

* Codemirror markdown implementation (#106)

* demo

* custom newline logic

* basic editor styling and buttons

* propogate styles

* validate and command structure for modals

* mobile safari event fix

* remove url field causing remount

* browser & mobile fix for link insertion

* override event passthrough to fix mobile

* fix modal state & disallow invalid url submission

* override paste behavior

* remove block flag in favor of newline insert

* cleanup before pr

* emit value from editor

* remove "a"

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Co-authored-by: Emma Alexia Triphora <emma@modrinth.com>
Co-authored-by: Carter <safe@fea.st>

lib/assets/icons/heading-1.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-heading-1"><path d="M4 12h8"/><path d="M4 18V6"/><path d="M12 18V6"/><path d="m17 12 3-2v8"/></svg>