Getting source: Add --depth 1 arguments (#4994)

* Getting source: Add --depth 1 arguments

The whole commit history isn't needed to compile the engine, which is the context of this docs page, so mention the way to avoid cloning all of it.

Also I've changed the second ``--branch`` argument to ``-b`` so the line wouldn't get out of bounds.

Co-authored-by: Max Hilbrunner <[email protected]>

development/compiling/getting_source.rst

@@ -32,19 +32,21 @@ the following in a terminal:
 ::
 
     git clone https://github.com/godotengine/godot.git
+    # You can add the --depth 1 argument to omit the commit history.
+    # Faster, but not all Git operations (like blame) will work.
 
 For any stable release, visit the `release page <https://github.com/godotengine/godot/releases>`__
 and click on the link for the release you want.
 You can then download and extract the source from the download link on the page.
 
 With ``git``, you can also clone a stable release by specifying its branch or tag
-after the ``--branch`` argument::
+after the ``--branch`` (or just ``-b``) argument::
 
     # Clone the continuously maintained stable branch (`3.x` as of writing).
-    git clone https://github.com/godotengine/godot.git --branch 3.x
+    git clone https://github.com/godotengine/godot.git -b 3.x
 
     # Clone the `3.2.3-stable` tag. This is a fixed revision that will never change.
-    git clone https://github.com/godotengine/godot.git --branch 3.2.3-stable
+    git clone https://github.com/godotengine/godot.git -b 3.2.3-stable
 
 There are also generally branches besides ``master`` for each major version.