Next round of improvements to markdown checks

[RobH123]

This change is 

[codecov]

Codecov Report

Merging #142 (449499b) into master (79c9680) will increase coverage by 0.02%.
The diff coverage is 42.55%.

@@            Coverage Diff             @@
##           master     #142      +/-   ##
==========================================
+ Coverage   45.46%   45.48%   +0.02%     
==========================================
  Files          22       22              
  Lines        3073     3100      +27     
  Branches      991     1006      +15     
==========================================
+ Hits         1397     1410      +13     
- Misses       1060     1063       +3     
- Partials      616      627      +11     

Impacted Files	Coverage Δ
src/core/BCS-usfm-grammar-check.js	54.66% <ø> (+2.35%)	⬆️
src/core/annotation-row-check.js	2.53% <0.00%> (-0.03%)	⬇️
src/core/file-text-check.js	91.17% <ø> (ø)
src/core/getApi.js	10.71% <ø> (ø)
src/core/manifest-text-check.js	4.81% <ø> (ø)
src/core/markdown-file-contents-check.js	90.38% <ø> (ø)
src/core/orig-quote-check.js	62.08% <ø> (ø)
src/core/ta-reference-check.js	89.58% <ø> (ø)
src/core/usfm-js-check.js	11.76% <ø> (ø)
src/core/usfm-text-check.js	56.34% <ø> (ø)
... and 10 more

---

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 79c9680...449499b. Read the comment docs.

[RobH123]

Probably good to get this fixes and small enhancements out before we start making changes to TSV files.

[mandolyte]

Reviewed 7 of 26 files at r1, 24 of 26 files at r2, 2 of 2 files at r3.
Reviewable status: complete! all files reviewed, all discussions resolved