web: cleanup description and add more original source links

web/charts/example/README.md

@@ -2,7 +2,7 @@ Examples of the [charts_flutter](https://pub.dev/packages/charts_flutter) packag
 
 Original source at [github.com/google/charts](https://github.com/google/charts).
 
-Copied from [github.com/google/charts](https://github.com/google/charts) at
+Copied from
-[35aeffe7c9](https://github.com/google/charts/commit/35aeffe7c96aa7d231c90fddd9766998545f1080).
+[commit 35aeffe7c9](https://github.com/google/charts/commit/35aeffe7c96aa7d231c90fddd9766998545f1080).
 
 With changes to run on the web.

web/dad_jokes/README.md

@@ -1 +1,4 @@
 A fun little app for groan-worthy dad jokes.
+
+Original source at
+[github.com/timsneath/dadjokes](https://github.com/timsneath/dadjokes/).

web/filipino_cuisine/README.md

@@ -1,6 +1,9 @@
 A sample that shows a visual recipe catalog for Filipino food.
 
 Contributed as part of the Flutter Create 5K challenge by John Mark Grancapal.
+Original source at
+[github.com/markgrancapal/filipino_cuisine](https://github.com/markgrancapal/filipino_cuisine).
+
 
 **Asset License**: All images used on this app are under the "CC0 - Creative Commons" license
 

web/gallery/README.md

@@ -1 +1,3 @@
-A [gallery](https://github.com/flutter/flutter/tree/master/examples/flutter_gallery) of Flutter widgets and UX studies.
+A gallery of Flutter widgets and UX studies.
+
+Original source on [GitHub](https://github.com/flutter/flutter/tree/master/examples/flutter_gallery).

web/spinning_square/README.md

@@ -1 +1,4 @@
 Just a spinning square. That's it. Super exciting.
+
+Original source on
+[GitHub](https://github.com/flutter/flutter_web/tree/master/examples/spinning_square).

web/timeflow/README.md

@@ -1,6 +1,8 @@
 A gentle animation that provides a calming experience to stressed developers.
 
 Contributed as part of the Flutter Create 5K challenge by Fabian Stein.
+Original source at
+[github.com/Fabian-Stein/timeflow](https://github.com/Fabian-Stein/timeflow).
 
 Timers and stopwatches aren’t the most peaceful gadgets, often reminding us of
 urgent tasks, deadlines and unpleasant appointments. Not in this case, Timeflow