Add single bundle mode for the build output

[agubler]

Adds an options to produce a single "main" bundle in the build output.

[codecov]

Codecov Report

Merging #148 into v3 will decrease coverage by 1.32%.
The diff coverage is 7.69%.

@@            Coverage Diff             @@
##               v3     #148      +/-   ##
==========================================
- Coverage   60.33%   59.01%   -1.33%     
==========================================
  Files           8        8              
  Lines         416      427      +11     
  Branches       93      103      +10     
==========================================
+ Hits          251      252       +1     
- Misses        165      175      +10

Impacted Files	Coverage Δ
src/dev.config.ts	23.4% <0%> (-2.18%)	⬇️
src/dist.config.ts	33.33% <0%> (-3.26%)	⬇️
src/base.config.ts	27.72% <0%> (-0.57%)	⬇️
src/main.ts	100% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6f1a204...a4bb4ca. Read the comment docs.