fix: cache markdown it instance and properly dispose shiki on config reload (#4321)

This results in over 5x speedup in build times of certain projects. But this comes at the cost of correctness. `createMarkdownRenderer` now ignores any arguments passed by user. But from our GitHub code search we didn't find any user passing options different than their siteConfig to this function. If you are doing that, please open an issue and we can discuss the best way forward.

---
Co-authored-by: Divyansh Singh <[email protected]>

Author: Barbapapazes

package.json

@@ -100,20 +100,20 @@
   "dependencies": {
     "@docsearch/css": "^3.6.2",
     "@docsearch/js": "^3.6.2",
-    "@shikijs/core": "^1.22.0",
-    "@shikijs/transformers": "^1.22.0",
-    "@shikijs/types": "^1.22.0",
+    "@shikijs/core": "^1.22.2",
+    "@shikijs/transformers": "^1.22.2",
+    "@shikijs/types": "^1.22.2",
     "@types/markdown-it": "^14.1.2",
     "@vitejs/plugin-vue": "^5.1.4",
-    "@vue/devtools-api": "^7.4.6",
+    "@vue/devtools-api": "^7.5.4",
     "@vue/shared": "^3.5.12",
     "@vueuse/core": "^11.1.0",
     "@vueuse/integrations": "^11.1.0",
     "focus-trap": "^7.6.0",
     "mark.js": "8.11.1",
     "minisearch": "^7.1.0",
-    "shiki": "^1.22.0",
-    "vite": "^5.4.8",
+    "shiki": "^1.22.2",
+    "vite": "^5.4.10",
     "vue": "^3.5.12"
   },
   "devDependencies": {
@@ -127,7 +127,7 @@
     "@mdit-vue/shared": "^2.1.3",
     "@polka/compression": "^1.0.0-next.28",
     "@rollup/plugin-alias": "^5.1.1",
-    "@rollup/plugin-commonjs": "^28.0.0",
+    "@rollup/plugin-commonjs": "^28.0.1",
     "@rollup/plugin-json": "^6.1.0",
     "@rollup/plugin-node-resolve": "^15.3.0",
     "@rollup/plugin-replace": "^6.0.1",
@@ -141,15 +141,15 @@
     "@types/markdown-it-emoji": "^3.0.1",
     "@types/micromatch": "^4.0.9",
     "@types/minimist": "^1.2.5",
-    "@types/node": "^22.7.5",
+    "@types/node": "^22.8.2",
     "@types/postcss-prefix-selector": "^1.16.3",
     "@types/prompts": "^2.4.9",
     "chokidar": "^3.6.0",
     "conventional-changelog-cli": "^5.0.0",
     "cross-spawn": "^7.0.3",
     "debug": "^4.3.7",
     "esbuild": "^0.24.0",
-    "execa": "^9.4.0",
+    "execa": "^9.5.1",
     "fs-extra": "^11.2.0",
     "get-port": "^7.1.0",
     "gray-matter": "^4.0.3",
@@ -164,31 +164,31 @@
     "markdown-it-mathjax3": "^4.3.2",
     "micromatch": "^4.0.8",
     "minimist": "^1.2.8",
-    "nanoid": "^5.0.7",
+    "nanoid": "^5.0.8",
     "ora": "^8.1.0",
     "p-map": "^7.0.2",
     "path-to-regexp": "^6.3.0",
-    "picocolors": "^1.1.0",
+    "picocolors": "^1.1.1",
     "pkg-dir": "^8.0.0",
-    "playwright-chromium": "^1.48.0",
+    "playwright-chromium": "^1.48.2",
     "polka": "^1.0.0-next.28",
     "postcss-prefix-selector": "^2.1.0",
     "prettier": "^3.3.3",
     "prompts": "^2.4.2",
     "punycode": "^2.3.1",
     "rimraf": "^6.0.1",
-    "rollup": "^4.24.0",
+    "rollup": "^4.24.2",
     "rollup-plugin-dts": "^6.1.1",
     "rollup-plugin-esbuild": "^6.1.1",
     "semver": "^7.6.3",
     "simple-git-hooks": "^2.11.1",
     "sirv": "^3.0.0",
     "sitemap": "^8.0.0",
     "supports-color": "^9.4.0",
-    "tinyglobby": "^0.2.9",
+    "tinyglobby": "^0.2.10",
     "typescript": "^5.6.3",
-    "vitest": "^2.1.2",
-    "vue-tsc": "^2.1.6",
+    "vitest": "^2.1.4",
+    "vue-tsc": "^2.1.8",
     "wait-on": "^8.0.1"
   },
   "peerDependencies": {
@@ -203,7 +203,7 @@
       "optional": true
     }
   },
-  "packageManager": "[email protected].1",
+  "packageManager": "[email protected].3",
   "pnpm": {
     "peerDependencyRules": {
       "ignoreMissing": [