Changing ion number to ion charge where appropriate

[andrewfullard]

📝 Description

Type: 🪲 bugfix

See issue #214. Likely requires changes on the TARDIS end if we want to completely remove the 1-indexed option.

🚦 Testing

How did you test these changes?

• Testing pipeline
• Other method (describe)
• My changes can't be tested (explain why)

☑️ Checklist

• I requested two reviewers for this pull request
• I updated the documentation according to my changes
• I built the documentation by applying the build_docs label

Note: If you are not allowed to perform any of these actions, ping (@) a contributor.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.30%. Comparing base (09bd62c) to head (c90ab06).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #408   +/-   ##
=======================================
  Coverage   58.30%   58.30%           
=======================================
  Files          30       30           
  Lines        2758     2758           
=======================================
  Hits         1608     1608           
  Misses       1150     1150           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.