Update SIGPLAN-AV page

[janpaulpl]

AV page changes

• The make serve command now has the --livereload flag.
• The addition of an About Us section that explains what we provide SIGPLAN conferences in more detail.
• Move up the information for General Chairs and Prospective Members to the top of the page for easy access.
• Reconfigure the way our Active / Emeritus members are displayed. Went from a bullet-point list to displaying our names and pictures from researchr.

Added the following files:

• _data/AVCommittee.yaml
• _includes/av-committee.liquid
• AV/index.md

[sampsyo]

Hello, @janpaulpl! It would be really helpful if you could include some commentary about what changes this entails so I can navigate around them—any chance you could write some notes?

Also, it looks like this includes a Python script to generate HTML. Did you know that this entire site is already generated HTML, including from data files with personnel listings like this? It uses Jekyll, and the data comes from various YAML files. For example, here's the listing of the executive committee:

SIGPLAN.github.io/_data/Committees.yaml

Lines 16 to 28 in 9bd36de

	Elected Members:
	- Chair: "[Andrew Myers](https://www.cs.cornell.edu/andru/) (Cornell University)"
	- Vice Chair: "[Anders Møller](https://cs.au.dk/~amoeller/) (Aarhus University)"
	- Members at Large:
	- Secretary: "[Ilya Sergey](https://ilyasergey.net/) (National University of Singapore)"
	- Treasurer: "[Alex Potanin](https://potanin.github.io/) (Australian National University)"
	- Awards Co-Chair: "[Alexandra Silva](https://alexandrasilva.org/) (Cornell University)"
	- Awards Co-Chair: "[Niki Vazou](https://nikivazou.github.io/) (IMDEA Software Institute)"
	- PAC Chair: "[Neel Krishnaswami](https://www.cl.cam.ac.uk/~nk480/) (University of Cambridge)"
	- Diversity and Mentoring Co-Chair: "[Brigitte Pientka](https://www.cs.mcgill.ca/~bpientka/) (McGill University)"
	- Diversity and Mentoring Co-Chair: "[Azalea Raad](https://www.soundandcomplete.org/) (Imperial College London)"
	- Past Chair: "[Jeff Foster](https://www.eecs.tufts.edu/~jfoster/) (Tufts University)"
	- Past Vice Chair: "[Anders Møller](https://cs.au.dk/~amoeller/) (Aarhus University)"

And then it gets formatted into HTML using Liquid templates; namely:

SIGPLAN.github.io/ContactUs.md

Line 11 in 9bd36de

{% include committee.liquid name="Elected Members" prefix=true header=true %}

https://github.com/SIGPLAN/SIGPLAN.github.io/blob/9bd36de7f4050a1a5b79f1fa191abaff7180edcd/_includes/committee-list.liquid

Do you think we could use that existing functionality to format the HTML you're looking for, instead of creating an ad hoc approach just for this one list?

[janpaulpl]

No problem @sampsyo! We've removed all the ad-hoc HTML generation and replaced it with Liquid which is much cleaner. The PR also has a description of the changes now.

[sampsyo]

Looks great; thanks!!