Update todo.txt

Added some points
Added links to all pages

Added links to all pages, contact, todo, index and about.
Added basic html

Added basic html, also created a jumbotron that is flush with the
navigation.
Added a header and some paragraphs

Added a header and some paragraphs. Also expanded the columns to 100%
witdth on the smallest devices and 50% on small to large displays.
Reduces font-size on .lead

Reduces font-size on text with the class lead
Added contributors heading

Added contributors heading and comment marking where it starts.
Added a table with contributors

Added a table with contributors with the rows number, name and role.