v0.3.0-beta.0

Changed implementation to avoid using command line utilities: xargs, cut, code. fzf output is now sent through named pipes and processed in the VSCode extension code. This avoids issues with having those utilities installed, having the wrong code on the path, and allows for implemeting arbitrary functionality beyond what the code command supports.

Any feedback welcome. I'll be testing this out myself and getting some colleagues to try it out. Hopefully this addresses #5 #2 and decrease dependence on system setup.