Added some preliminary explanation to the description of Householder
reflectors to make explaining Hessenberg form easier.
Also updated the pseudocode to make it easier to work.
Some more small edits to the description of the algorithm for QR
decomposition using Householder reflectors.
Added pseudocode for Hessenberg form algorithm,
fixed pseudocode for Householder algorithm,
and fixed some formatting.
Added an interesting side note.
Merge pull request #340 from insertinterestingnamehere/householder

Householder