🚚(frontend) delete useless nesting

Update frontend to be the root folder of the frontend sources,
instead of nesting them in a folder named as the application.

We only work on a single frontend app as of today, nesting
sources doesn't add any value, even though the initial organization
was more extensible.

src/frontend/.gitignore

@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?