Blob to tree readme updates

[rockhowse]

Love the role, trying to use the documentation the links were failing for two reasons:

1. the URLs were hard coded to blob instead of what appears to be a new tree folder (havn't seen this before)
2. The names of the files in the links are lowercase readme.md and the files are actually uppercase README.md

I am unsure if the official Galaxy documentation format accepts relative URLs, but the changes linked appear to allow me to link directly to the documentation from my branch.

Totally open to changing the format either way, but ideally links from the main documentation page in github should be functioning.

I am not sure how to test these officially in galaxy 🤔

[rockhowse]

After checking out galaxy, I am unsure it supports relative URLs, so this works both in my branch and ideally should work in galaxy 😄

[ericsysmin]

Thanks! Things probably changed because it used to work.