add parser for Hangouts/Hangouts.json

[karlicoss]

also oddly, my takeout for 2014 has Hangouts.json and Hangouts2.json (with similar size), the diff shows like 10% of lines, but hard to tell what's actually different, seems very random
all later takeouts only have single Hangouts.json

[glenviewjeff]

I used jq along with the help of ChatGPT to write the jq code. Here's the code I ended up with to parse Google Chat JSON and generate output I found tasteful:

jq -r '.messages[] | if has("created_date") then "(.created_date | strptime("%A, %B %d, %Y at %I:%M:%S %p UTC") | strftime("%m/%d/%y %I:%M %p")):(.creator.name | split(" ")[0]) - (.text)" else "(.creator.name | split(" ")[0]) - (.text)" end' < messages.json > messages.txt