Fixed cross references

The cross references to other chapters have been messed up during the time and were rarely correct.
I worked through the whole guide to fix the cross references so that they will now point to the correct chapter / paragraph (which are now also reachable via a link).
There were also a few tiny typos which I fixed along the line (e.g. componet instead of component).
Only in pagestoring.gdoc, maven_1.gdoc and contributing.gdoc I added a small paragraph / sentence else there no additional content.

Since I am not sure if only a patch for the gdoc-files is needed or also for the generated HTML files (the guide was not clear on that one I will provide two patches.