fix links especially markdown links in sidebar

[MarcSkovMadsen]

Closes #4221

[codecov]

Codecov Report

Merging #4222 (b08f5cd) into master (e02a0f2) will increase coverage by 0.00%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #4222   +/-   ##
=======================================
  Coverage   83.05%   83.05%           
=======================================
  Files         235      235           
  Lines       34171    34171           
=======================================
+ Hits        28380    28381    +1     
+ Misses       5791     5790    -1     

Flag	Coverage Δ
ui-tests	37.91% <ø> (+<0.01%)	⬆️
unitexamples-tests	74.19% <ø> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
panel/pane/base.py	87.91% <0.00%> (-0.84%)	⬇️
panel/io/state.py	70.68% <0.00%> (+0.17%)	⬆️
panel/tests/util.py	91.26% <0.00%> (+1.94%)	⬆️

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[philippjfr]

Thanks, was about to make the same changes.

[philippjfr]

Looks good, thank you!