firebase: add page (#4420)

pages/common/firebase.md

@@ -0,0 +1,25 @@
+# firebase
+
+> Firebase Command Line Interface (CLI) Tools.
+> Used to test, manage, and deploy your Firebase project from the command line.
+> More information: <https://github.com/firebase/firebase-tools>.
+
+- Login:
+
+`firebase login`
+
+- Display the help:
+
+`firebase help`
+
+- List existing firebase projects:
+
+`firebase project:list`
+
+- Setup a firebase in the current directory:
+
+`firebase init {{options}} {{feature}}`
+
+- Deploy code and assets to the project in the current directory:
+
+`firebase deploy`