Add details to CONTRIBUTING.md

[melange396]

Add some more details/specifics about new indicator development and set-up to the instructions at https://github.com/cmu-delphi/covidcast-indicators/blob/main/.github/CONTRIBUTING.md :

• Add the indicator to the list in

  covidcast-indicators/Jenkinsfile

  Line 13 in f011857

  def indicator_list = ["backfill_corrections", "changehc", "claims_hosp", "google_symptoms", "hhs_hosp", "nchs_mortality", "quidel_covidtest", "sir_complainsalot", "doctor_visits", "nwss_wastewater"]

  (perhaps mentioning that here)
• Add the indicator to the list in

  covidcast-indicators/.github/workflows/create-release.yml

  Line 64 in f011857

  indicator_list=("changehc" "claims_hosp" "doctor_visits" "google_symptoms" "hhs_hosp" "nchs_mortality" "quidel_covidtest" "sir_complainsalot")

• Add parameters to an indicator-specific json file in https://github.com/cmu-delphi/covidcast-indicators/tree/main/ansible/templates/
• Add (typically "secret") variables in https://github.com/cmu-delphi/covidcast-indicators/blob/main/ansible/vars.yaml and https://github.com/cmu-delphi/covidcast-indicators/blob/main/ansible/vault.yaml
• Add configs for Sir Complains-a-Lot alerting in https://github.com/cmu-delphi/covidcast-indicators/blob/main/sir_complainsalot/params.json.template and https://github.com/cmu-delphi/covidcast-indicators/blob/main/ansible/templates/sir_complainsalot-params-prod.json.j2