Update Wire fillet docstring

[lorenzncode]

PR #1549 added fillet with docstring that says "Currently only open wires are supported". PR #1573 added support for closed wires but the docstring was not update.

There is also corruption of the Sphinx doc summary:

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.92%. Comparing base (edabe5e) to head (d2c324c). Report is 13 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1630   +/-   ##
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  Coverage   94.92%   94.92%           
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  Files          28       28           
  Lines        6263     6263           
  Branches     1271     1271           
=======================================
  Hits         5945     5945           
  Misses        192      192           
  Partials      126      126           

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[lorenzncode]

I noticed some corruption in the Sphinx docs for new Workplane special methods. It's important to add empty line separating the field list in the docstring.

[adam-urbanczyk]

Looks good @lorenzncode , I'll just go ahead and merge this. Thanks!