Add PR template and git-webkit configuration

* .github/pull_request_template.md: Added.
* metadata/git_config_extension: Added.

Author: JonWBedard

.github/pull_request_template.md

@@ -0,0 +1,15 @@
+# Pull Request Template
+
+Pull request descriptions should be based on the commit message of the commit (or commits) being reviewed.
+
+## Commit Message Template
+
+<pre>
+< change title >
+<a href="https://github.com/WebKit/Documentation/issues">(Optional) https://github.com/WebKit/Documentation/issues/###</a>
+
+* path/changed.ext:
+* o-path/o-file.ext:
+
+</pre>
+

metadata/git_config_extension

@@ -0,0 +1,7 @@
+[pull]
+        rebase = true
+[webkitscmpy]
+        pull-request = append
+        history = disabled
+        update-fork = true
+        auto-check = true