♻️(y-provider) replace y-webrtc-signaling by server-y-provider

We replace the y-webrtc-signaling app by
the server-y-provider server.
The server-y-provider server uses @hocuspocus to
do collaborative editing on docs.

src/frontend/servers/y-provider/.eslintrc.cjs

@@ -0,0 +1,14 @@
+module.exports = {
+  root: true,
+  extends: ['impress/next'],
+  parserOptions: {
+    tsconfigRootDir: __dirname,
+    project: ['./tsconfig.json'],
+  },
+  settings: {
+    next: {
+      rootDir: __dirname,
+    },
+  },
+  ignorePatterns: ['node_modules', '.eslintrc.js'],
+};