My dotfiles for running an i3-based environment within WSL, working as of Windows Fall Creators Update (version 1709).
I wrote a bit about this setup here.
Included are configuration files and scripts for:
When running with a HiDPI display, make sure to override
VcXsrv.exe's default scaling settings to application-controlled
(Compatibility tab of Properties). Otherwise, Windows will incorrectly scale it, capping your X server to around half the
resolution it should be displaying at (e.g. 1600p instead of 4K).