Changed routing framework from mux to Gin.

Swagger doc is now included in the application.
A fronted can now be hosted from the application.

cmd/frontend/.gitignore

@@ -0,0 +1,21 @@
+.DS_Store
+node_modules
+/dist
+
+# local env files
+.env.local
+.env.*.local
+
+# Log files
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+
+# Editor directories and files
+.vscode
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?