Fix broken docs links

[thehomebrewnerd]

Fix broken docs links

Several links in the documentation and code were still linking to docs.featuretools.com. Updated these links to point to the corresponding file in the new documentation at featuretools.alteryx.com.

Closes #1299

[codecov]

Codecov Report

Merging #1313 (c4bf719) into main (6f7cead) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1313   +/-   ##
=======================================
  Coverage   98.38%   98.38%           
=======================================
  Files         135      135           
  Lines       14496    14496           
=======================================
  Hits        14262    14262           
  Misses        234      234           

Impacted Files	Coverage Δ
featuretools/computational_backends/utils.py	95.54% <ø> (ø)
featuretools/utils/plot_utils.py	92.00% <ø> (ø)

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[rwedge]

Looks good