Although configure.ac will for the presence of bison, the READMEs didn't say that was a required program. Patch from Carlos Torres

Remove conflict markers in README, and add mailing-list link to both READMEs. Noticed by stsp

Fix some typos. From Christian "naddy" Weisgerber

Add a .github/README.md file so that the read-only clone of GoT on Github, which is used for CI purposes, explains the project. Also, update the README.portable vesion to patch.