Onboarding post

[signekb]

I have started an "Onboarding post" as well as updated the "Software we use" and "Creating PUML images" entries.

Issues currently included in this pr: #23 #25 #28 #29

Questions that came up while doing this:

• Do we actually use RStudio for Seedcase? (if no, should it be removed from the Software list? If yes, should it be added in a decision post in the seedcase-project repo?)
• When should new team members install the recommended software? I was able to start reviewing the documentation because I had much of the needed software installed on my own computer already. Should new team members install recommended software on their own computer in case they have to wait a couple of weeks, like I had to?
• Framing of the onboarding post: Should this post be for new team members only or also for external contributors? Currently, I have written it for future team members.

[lwjohnst86]

To address the three points:

1. You could use RStudio to contribute to the website, but you are right, we should just remove it since we can't use RStudio for anything else. (well we could, but it would be painful).
2. Hm, good question. I think we could recommend installing the stuff right away. I mean, I use my personal computers for work all the time (since I use Linux)
3. Hmm, another good question. I think having one would work well, since external contributors probably need to know a lot of the similar things that we need to know. So framing it as onboarding for someone who contributes more than once.

[lwjohnst86]

Just minor edits, thanks!!