Update contributing instructions to include pandoc

[gsheni]

• Update Dockerfile instructions
• Add pandoc to contributing.md

[codecov]

Codecov Report

Merging #2104 (10f35ba) into main (19fe98d) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #2104   +/-   ##
=======================================
  Coverage   99.20%   99.20%           
=======================================
  Files         143      143           
  Lines       16569    16569           
=======================================
  Hits        16437    16437           
  Misses        132      132           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 19fe98d...10f35ba. Read the comment docs.

[thehomebrewnerd]

@gsheni I may be a bit out of the loop on this PR, but did something change that requires us to now install pandoc when we didn't need to previously?

[gsheni]

@thehomebrewnerd We always needed to install pandoc to build the docs. This just adds it to the contributing doc

[thehomebrewnerd]

@thehomebrewnerd We always needed to install pandoc to build the docs. This just adds it to the contributing doc

Hmm...ok. I never recall installing it previously, but maybe I have just forgotten. I definitely can't build now without installing though.

[thehomebrewnerd]

I'm not well-versed enough in Docker to know if the updates for the dockerfile all good, but they seem ok to me.

[rwedge]

Docker image worked for me!