docs: fix Unicode text in Fraktur font

[edemaine]

Fix Fraktur font documentation by correcting spelling and not attempting to use the Unicode symbols in text mode.

Fixes #3867

What is the previous behavior before this PR?

What is the new behavior after this PR?

[edemaine]

@untitledunrevised Thanks for the report! Would you like to review this fix? See https://deploy-preview-3873--katex.netlify.app/docs/supported#math-alpha for a docs preview.

[codecov]

Codecov Report

Merging #3873 (6573753) into main (fc5af64) will decrease coverage by 0.17%.
Report is 1 commits behind head on main.
The diff coverage is 100.00%.

❗ Current head 6573753 differs from pull request most recent head 3de36c5. Consider uploading reports for the commit 3de36c5 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3873      +/-   ##
==========================================
- Coverage   93.15%   92.99%   -0.17%     
==========================================
  Files          91       91              
  Lines        6792     6779      -13     
  Branches     1579     1576       -3     
==========================================
- Hits         6327     6304      -23     
- Misses        429      437       +8     
- Partials       36       38       +2     

Files	Coverage Δ
src/symbols.js	100.00% <100.00%> (ø)

... and 5 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ab32359...3de36c5. Read the comment docs.

[untitledunrevised]

Looks Good To Me
Another thing is: Is a space needed to insert in Bold Fraktur?