GitLab

As the links was [[link]] the last `]` was included in the url.

* Switch from decimal to symbol in most places and add a description of what a symbol is per Lukasz.

* Add list of algorithmic tasks.
* Detail what is stored in /tmp/neural_gpu/ (default location).
* Detail that one should hit Ctrl-C to stop the training process.
* Add sections around decoding and animation, but couldn't get those to work myself. Still worth having in the docs.