DOC: Developer doc enhancements

[toryhaavik]

Closes #1956

[codecov]

Codecov Report

Merging #1960 into master will decrease coverage by 1.62%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1960      +/-   ##
==========================================
- Coverage   87.76%   86.14%   -1.63%     
==========================================
  Files          93       93              
  Lines       17088    17088              
  Branches     2159     2159              
==========================================
- Hits        14997    14720     -277     
- Misses       1683     1963     +280     
+ Partials      408      405       -3

Impacted Files	Coverage Δ
ibis/bigquery/client.py	41.1% <0%> (-53.39%)	⬇️
ibis/bigquery/compiler.py	59.92% <0%> (-37.5%)	⬇️
ibis/bigquery/udf/api.py	80.48% <0%> (-14.64%)	⬇️
ibis/impala/compiler.py	91.23% <0%> (-5.2%)	⬇️
ibis/pandas/client.py	85.54% <0%> (-3.47%)	⬇️
ibis/bigquery/api.py	63.33% <0%> (-3.34%)	⬇️
ibis/expr/schema.py	90.1% <0%> (-1.1%)	⬇️
ibis/sql/compiler.py	94.26% <0%> (-0.39%)	⬇️
ibis/expr/api.py	92.33% <0%> (-0.37%)	⬇️
ibis/impala/client.py	78.27% <0%> (+0.5%)	⬆️

[xmnlab]

@toryhaavik that looks pretty good. should it contain information about numpy docstring default?

[toryhaavik]

@xmnlab sure, that's a good one, i'll add that in now.

[xmnlab]

@toryhaavik looks great! thanks for working on that.