Bulid for Windows 10

[ramisedhom]

I tried today to build pomo on Windows 10 and it's successfully done:

Requirements:

• Go 1.14.2 Windows 64
• TDM-GCC (tdm64-gcc-9.2.0)
• Git

Steps

1. Ensure Go, gcc, git in the PATH environment variable
2. Open command prompt and exec: go get github.com/kevinschoon/pomo
   Got this message: package github.com/gizak/termui: no Go files in C:\Users\YOURUSERID\go\src\github.com\gizak\termui
3. Go to this path C:\Users\YOURUSERID\go\src\github.com\kevinschoon\pomo and run: go build .. pomo.exe is created and ready

[kevinschoon]

Thanks for contributing this @ramisedhom, feel free to update the readme in a PR!