add a page for code and coffee challenges

[karimamer]

adding a page where we can put are challenges and links to the solutions let's say gists for small challenges and links to github if the challenge is big

[rogerhoward]

👍

Suggestion: use posts+categories to dynamically build it - basically, copy the members list mechanism. This way, each challenge can be added as a single .md file.

[karimamer]

👍 getting it done today in the evening