remove salt from salvage

[deltanedas]

About the PR

replaced it with more coal spawners
coal in the random ore spawner is a bit more common so theres a stronger surplus to share with chem

Why / Balance

• salv hates salt because its annoying
• chem hates salt because its fucking salt you never run out of sodium or chlorine so grinding it just a waste of your time that you would only do to make salv not feel like they completely wasted their time running to chem
• chem loves coal because carbon = life, and carbon is usually the only reason you buy a chemvend restock at all

Requirements

• I have read and am following the Pull Request and Changelog Guidelines.
• I have added media to this PR or it does not require an ingame showcase.

Breaking changes

Changelog
🆑

• remove: Removed salt ore in favour of coal. Give the chemists carbon!