[Material] Material theme builder (#313)

* Initial version.

* Applied theming.

* Updated UI

- Updated ThemeData to baseline values

* Update readme

Update readme

* Update readme

* Update readme

* [INDEX] Adding a listing for this.

* [Material Theme Builder] PR feedback and updating for new text theme API.

* [Material Theme Builder] More PR feedback.

* [Material Theme Builder] Adding to Travis.

* [Material Theme Builder] Rebase conflicts.

* [Theme Generator] Adding 1 link to the readme.

Co-authored-by: yasmineevjen <yasmineevjen@users.noreply.github.com>

material_theme_builder/ios/.gitignore

@@ -0,0 +1,32 @@
+*.mode1v3
+*.mode2v3
+*.moved-aside
+*.pbxuser
+*.perspectivev3
+**/*sync/
+.sconsign.dblite
+.tags*
+**/.vagrant/
+**/DerivedData/
+Icon?
+**/Pods/
+**/.symlinks/
+profile
+xcuserdata
+**/.generated/
+Flutter/App.framework
+Flutter/Flutter.framework
+Flutter/Flutter.podspec
+Flutter/Generated.xcconfig
+Flutter/app.flx
+Flutter/app.zip
+Flutter/flutter_assets/
+Flutter/flutter_export_environment.sh
+ServiceDefinitions.json
+Runner/GeneratedPluginRegistrant.*
+
+# Exceptions to above rules.
+!default.mode1v3
+!default.mode2v3
+!default.pbxuser
+!default.perspectivev3