Add links back to the source repo, for easy maintenance

Change-Id: I6d31040c23863ea20f0e6f4d7e3f9e02673c7acd
Signed-off-by: Denis Roy <denis.roy@eclipse-foundation.org>

README.md

diff --git a/README.md b/README.md
index b525eea..22d28c7 100644
--- a/README.md
+++ b/README.md
@@ -11,3 +11,7 @@
 Copy the file `gerrit-eclipsestyle.html` into the Gerrit site's `plugins`
 directory. There is no need to restart, once the file was copied, Gerrit
 will detect the new PolyGerrit plugin after a few moments and will use it.
+
+## Source
+
+https://git.eclipse.org/r/admin/repos/git.eclipse.org/gerrit-eclipsetheme 
\ No newline at end of file

gerrit-eclipsestyle.html

diff --git a/gerrit-eclipsestyle.html b/gerrit-eclipsestyle.html
index eb4c58b..9048104 100644
--- a/gerrit-eclipsestyle.html
+++ b/gerrit-eclipsestyle.html
@@ -11,6 +11,7 @@
   See the License for the specific language governing permissions and
   limitations under the License.
   -->
+  <!--  Source URL: https://git.eclipse.org/r/admin/repos/git.eclipse.org/gerrit-eclipsetheme -->
   <script>
     'use strict';
     Gerrit.install(plugin => {