Reorganize milestone and update software development plan

[K20shores]

Milestones

Make a spreadsheet that lists all milestones in all projects

• Name
• Project
• Priority

Remove milestone numbers from milestones Any completed milestones should be placed in a milestone document in an archive folder for that project

Software development plan

Remove the granularity associated with the milestone breakdown

[K20shores]

@mattldawson @boulderdaze Since this isn't an issue and I can't make a PR, i'm tagging you here. I think I've completed this. Please let me know your thoughts

The milestone spreadsheet is here

I also updated the software development plan

[boulderdaze]

Looks good!!

[mattldawson]

looks good to me too!