Simplify API for exposing tRPC.

[jsonnull]

By passing in contextBridge, it's no longer required to pass the "electronTRPC" variable name which was hard-coded and couldn't be changed.

This also lets us change the name in the future without requiring changes when the package is upgraded.

[codecov-commenter]

Codecov Report

Merging #10 (06cbe34) into main (2ed54f9) will decrease coverage by 1.74%.
The diff coverage is 0.00%.

❗ Current head 06cbe34 differs from pull request most recent head 9cb8f3d. Consider uploading reports for the commit 9cb8f3d to get more accurate results

@@            Coverage Diff             @@
##             main      #10      +/-   ##
==========================================
- Coverage   45.69%   43.94%   -1.75%     
==========================================
  Files           8        8              
  Lines         151      157       +6     
  Branches       12       12              
==========================================
  Hits           69       69              
- Misses         82       88       +6     

Impacted Files	Coverage Δ
src/main/exposeElectronTRPC.ts	0.00% <0.00%> (ø)

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