Added textarea box for code.
Generate graphs of back propagation.

Generate several back propagation error graphs in images/graphs.
Added CSS for h3.
Added textarea box for code.
Generate graphs of back propagation.

Generate several back propagation error graphs in images/graphs.
Added CSS for h3.
Merge branch 'website' of https://github.com/ChristopheSteininger/Topics into website
Changed CSS to improve fonts for headers and body text.
Add graph to backpropagation site.
Merge branch 'website' of https://github.com/ChristopheSteininger/Topics into website
Reformatted image code in backpropagation.html to match layout.
Updated textarea for code to be the correct size and readonly/unresizable.
Fixed some formatting issues for the textarea.
Moved CSS into its own folder, and added syntax highlighting for pseudocode.
Update perceptron page from pdf file.
Added images and made some parts transparent to look better with website.