git ignore: add page (#3978)

pages/common/git-ignore.md

@@ -0,0 +1,12 @@
+# git ignore
+
+> Generate .gitignore files from predefined templates.
+> More information: <https://docs.gitignore.io/install/command-line>.
+
+- List available templates:
+
+`git ignore list`
+
+- Generate a .gitignore template:
+
+`git ignore {{item_a,item_b,item_n}}`