docs(image): add content warnings to image function jsdocs

[ejcheng]

closes #1783

Adds disturbing image warnings to jsdocs for each function in the image module

@ST-DDT Should I also add something about usage limits? #1783 (comment)

[codecov]

Codecov Report

Merging #2159 (278751d) into next (c173150) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

❗ Current head 278751d differs from pull request most recent head 43eeeb4. Consider uploading reports for the commit 43eeeb4 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             next    #2159      +/-   ##
==========================================
- Coverage   99.60%   99.59%   -0.01%     
==========================================
  Files        2607     2607              
  Lines      244977   245013      +36     
  Branches     1151     1150       -1     
==========================================
+ Hits       244010   244032      +22     
- Misses        940      954      +14     
  Partials       27       27              

Impacted Files	Coverage Δ
src/modules/image/providers/lorempicsum.ts	92.30% <100.00%> (+0.58%)	⬆️
src/modules/image/providers/placeholder.ts	100.00% <100.00%> (ø)
src/modules/image/providers/unsplash.ts	100.00% <100.00%> (ø)

... and 6 files with indirect coverage changes

[xDivisionByZerox]

@ST-DDT Should I also add something about usage limits? #1783 (comment)

I'm not him, but yes I think you should. You cross reference #1783 which describes both doc changes (warning and limit usage).