Add preinstall hook for allow-only yarn (#3108)

* Add warning if npm or pnpm is used.

* Rename docs to documentation as link

docs/.vitepress/config.ts

@@ -54,7 +54,7 @@ export default defineConfig({
 function nav(): DefaultTheme.NavItem[] {
 	return [
 		{ text: "Features", link: "/features.md" },
-		{ text: "Docs", link: "/docs/introduction/getting-started.md", activeMatch: "/docs/" },
+		{ text: "Documentation", link: "/docs/introduction/getting-started.md", activeMatch: "/docs/" },
 		{ text: "Team", link: "/team.md" },
 		{ text: "Demo", link: "https://demo.hestiacp.com:8083/" },
 		{ text: "Forum", link: "https://forum.hestiacp.com/" },

package.json

@@ -13,6 +13,7 @@
 		"lint": "prettier --check . && eslint web/js/ && stylelint web/css/src/**/*.css && markdownlint *.md docs/**/*.md",
 		"lint-staged": "lint-staged",
 		"format": "prettier --write .",
+		"preinstall": "npx only-allow yarn",
 		"postinstall": "husky install"
 	},
 	"packageManager": "yarn@3.3.0",