minor corrections

- Explained the sblock question
- There are no 'paths'. There is no 'flow'. There are only links!
- Moved the explanation of what the blocks do to a more logical place.
As discussed in the mails and summarized in this document:
https://github.com/NorfairKing/microblx_documentation/blob/master/org/spelling.org

This should be the right naming convention. I have sent a mail about this to the mailing list.
The organisation 'microblx' repository should be named 'ubx'.