Highlights numbers in java

[serhack]

No description provided.

[alecthomas]

Thanks for the PR! There are tests for the lexer if you'd like to extend them, to verify everything is working. You can run them with:

./bin/go test ./lexers/...

To update the test, edit ./lexers/tesdata/java.actual to add the appropriate syntax, and run the above again. It should fail because the expected state is now different.

If the actual result looks correct run the following to finalise it:

RECORD=true ./bin/go test ./lexers

[serhack]

Thanks, those comments are pure gold for me! :) Honestly I feel like a little bit of challenge understanding how to contribute to Chroma but it's nice to have such welcoming messages!