Document address argument to pn.serve

[philippjfr]

Fixes #1364

[codecov]

Codecov Report

Merging #1435 into master will decrease coverage by 0.01%.
The diff coverage is 77.77%.

@@            Coverage Diff             @@
##           master    #1435      +/-   ##
==========================================
- Coverage   87.90%   87.89%   -0.02%     
==========================================
  Files         135      135              
  Lines       14854    15071     +217     
==========================================
+ Hits        13057    13246     +189     
- Misses       1797     1825      +28     

Impacted Files	Coverage Δ
panel/io/notebook.py	58.64% <0.00%> (ø)
panel/tests/test_server.py	100.00% <ø> (ø)
panel/io/server.py	62.63% <80.00%> (+0.06%)	⬆️
panel/viewable.py	69.77% <100.00%> (ø)
panel/config.py	40.72% <0.00%> (-5.81%)	⬇️
panel/tests/widgets/test_button.py	100.00% <0.00%> (ø)
panel/pipeline.py	89.40% <0.00%> (+0.83%)	⬆️
panel/links.py	85.56% <0.00%> (+1.05%)	⬆️
panel/widgets/button.py	85.71% <0.00%> (+2.38%)	⬆️
... and 1 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 c5d72bb...4915d9e. Read the comment docs.