fixed `ds.xroms.div` and `ds.xroms.div_norm`

[kthyng]

fixed ds.xroms.div and ds.xroms.div_norm in the case that u and v need to be calculated from other velocities like east and north

[codecov-commenter]

Codecov Report

Merging #52 (85f0e93) into main (20668af) will decrease coverage by 0.52%. The diff coverage is 37.50%.

:exclamation: Your organization is not using the GitHub App Integration. As a result you may experience degraded service beginning May 15th. Please install the Github App Integration for your organization. Read more.

@@            Coverage Diff             @@
##             main      #52      +/-   ##
==========================================
- Coverage   84.40%   83.88%   -0.52%     
==========================================
  Files          17       17              
  Lines        1872     1893      +21     
==========================================
+ Hits         1580     1588       +8     
- Misses        292      305      +13     

Flag	Coverage Δ
unittests	83.88% <37.50%> (-0.52%)	:arrow_down:

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

Files Changed	Coverage Δ
xroms/accessor.py	73.26% <37.50%> (-2.77%)	:arrow_down: