Checklist

Required

• I wrote the PR title in conventional commit format.
• I ran the code formatter.
• I linked any relevant issues using github keyword syntax so it can be closed automatically.
• I have committed my changes to new branch that isn't main so it won't cause conflict when updating main branch later.

Purpose of change

Some changes to the mapgen cs_tire_shop such as using regional terrain, replacing the wooden floor inside the store with concrete floor and change certain symbols to try to make the mapgen more uniform with the other stores.

Describe the solution

Replace non-regional outdoor terrain with pseudo-regional terrain.
Replace t_grate inside the shop with t_grate_indoor

Describe alternatives you've considered

none

Additional context

Before:

After: