Fix existing markdown lint issues

[MrAlias]

Adding skipping of the single title header level options in markdownlint because the website docs do this.

[codecov]

Codecov Report

Merging #1866 (27cfb29) into main (08f4c27) will decrease coverage by 0.0%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##            main   #1866     +/-   ##
=======================================
- Coverage   78.7%   78.7%   -0.1%     
=======================================
  Files        137     137             
  Lines       7343    7343             
=======================================
- Hits        5785    5784      -1     
  Misses      1317    1317             
- Partials     241     242      +1     

Impacted Files	Coverage Δ
sdk/trace/batch_span_processor.go	85.6% <0.0%> (-1.6%)	⬇️
exporters/trace/jaeger/jaeger.go	92.8% <0.0%> (+0.5%)	⬆️