Adds few Zig CLI commands

[mgxm]

Zig formatter

By default the value of zig-format-on-save is set to t, meaning that the code is automatically formatted before saves, to disable it, you can set it to nil. Besides that, you can toggle the behavior on certain buffers using M-x zig-toggle-format-on-save.

adds defcustom:

• zig-format-on-save Format buffers before saving using zig fmt.
• zig-zig-bin Path to zig executable.

adds defun:

• zig-toggle-format-on-save Switch "format before save" on the current buffer.
• zig-format-buffer Format the current buffer using the zig fmt.

Interactive commands

• zig-compile
• zig-build-exe
• zig-build-lib
• zig-build-obj
• zig-run
• zig-test-buffer

Default keybindings

C-c C-b runs zig-build C-c C-f runs zig-format-buffer C-c C-r runs zig-run C-c C-t runs zig-test-buffer

Closes: #12

[AndreaOrru]

Hi, sorry for the late answer. I like this - as soon as I get a chance to test and review it, I'll consider it for merging.

[AndreaOrru]

Looks good! Thanks for the contribution! Again sorry for the late answer, I've been off the grid for a while.