[refactor] update default renderer's error message.

[joshuaellis]

What:

Improve error message from our auto-detect-renderer function for users who are bundling.

Why:

Based on the feedback from #544

How:

Update the err msg & correct the test.

Checklist:

• Tests
• Ready to be merged
  

[codecov]

Codecov Report

Merging #547 (892cdfe) into master (d980fc0) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master      #547   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           14        14           
  Lines          210       210           
  Branches        23        23           
=========================================
  Hits           210       210           

Impacted Files	Coverage Δ
src/pure.ts	100.00% <ø> (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 d980fc0...892cdfe. Read the comment docs.