Add zipped cov file BOSSDR11LyaF.cov.gz
Update README instructions
Add .gitignore file to ignore BOSSDR11LyaF.cov
Update baofit with zipped DR11 autocorrelation cov file

* Add zipped BOSSDR11LyaF cov file.

* Update README instructions

* Add .gitignore file to ignore unzipped BOSSDR11LyaF cov file