Add a space after a colon in Gerrit-style git footer examples.

Follow up to https://crrev.com/747851 to provide good examples to
readers in the documentation.

Change-Id: I14e1aa32abce51c9ae1f7499737ff612e440733c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2212962
Reviewed-by: Henrique Ferreiro <[email protected]>
Commit-Queue: Lei Zhang <[email protected]>
Cr-Commit-Position: refs/heads/master@{#771201}
diff --git a/docs/accessibility/patts.md b/docs/accessibility/patts.md
index 637be7885..719d97c 100644
--- a/docs/accessibility/patts.md
+++ b/docs/accessibility/patts.md
@@ -101,8 +101,8 @@
 
 ```
 git commit -a
-  Bug:chromium:12345
-  Test:Write what you tested here
+  Bug: chromium:12345
+  Test: Write what you tested here
 repo upload .
 ```