3.0 Support context

If enabled with -C it will grep for the location +- a few lines and send it as deep context.
In our projects this resulted in way better translations.

Especially if you have a lot of buttons with different descriptions and translate into German or French.

What's Changed

• adding context by greping the source code by @tzdesign in #12

Full Changelog: v2.0.4...v3.0.0