tightened home page text.
Update FITS-header.ipynb
Update plot-catalog.ipynb

added description.
Update Quantities.ipynb

added description.
fix comma
fix desc location
Update FITS-header.ipynb

added description.
Update FITS-images.ipynb

added description.
replace titles
Merge branch 'master' of github.com:astropy/astropy-tutorials
Update FITS-tables.ipynb

added description.
Merge branch 'master' of github.com:astropy/astropy-tutorials
added descriptions to index
Update index_template.html

Tweaked Feedback and Contributions text. 
- Added links to repo, create a new issue, and list of open issues.
- Removed text that referred to link on top of each tutorial to repo. As far as i can tell, that link doesnt exist.
remove reference to pylab
Merge branch 'master' of github.com:astropy/astropy-tutorials
typo
typo
missing plt
Convert UVES tutorial to ipython notebook format