Add callouts support

Adds a colour palette
Adds homemade remark-callouts package
Adds tabler icons dependency

packages/website/package.json

@@ -33,6 +33,7 @@
     "rehype-katex-svelte": "1.2",
     "rehype-slug": "^6.0.0",
     "remark-abbr": "^1.4.2",
+    "remark-callouts": "workspace:^",
     "remark-footnotes": "2",
     "remark-frontmatter": "^5.0.0",
     "remark-gfm": "^4.0.0",
@@ -74,6 +75,7 @@
     "@octokit/types": "^13.5.0",
     "@resvg/resvg-js": "^2.6.2",
     "@steeze-ui/svelte-icon": "^1.5.0",
+    "@tabler/icons-svelte": "^3.11.0",
     "@tusbar/cache-control": "^1.0.2",
     "@uiw/codemirror-theme-github": "^4.22.2",
     "Notes": "file:Notes-1.0.0.tgz",