Update Readme.md

Signed-off-by: Aymeric Brisse <aymeric.brisse@perfect-memory.com>
Update tmTheme file, mainly fontStyle:foreground updates.

Some entries have been added:

- Variable Parameter
- Class
- String quoted double
- Embedded source

Signed-off-by: Aymeric Brisse <aymeric.brisse@perfect-memory.com>