fix!: correct site service crs to EPSG:4269 (NAD83) (#169)

The nwis site service (and the USGS more broadly) uses the NAD83 crs.

64a575d introduced a bug that hard coded the nwis module's  crs to
EPSG:4236 -- Hu Tzu Shan 1950 (https://epsg.io/4236). I guarantee
64a575d meant to hard code _EPSG:4326_ -- WGS84. It appears it was fat
fingered and missed in #143's PR review (it happens to the best of us:)).

In either case, EPSG:4326 is still _technically_ the wrong crs. For example:

https://waterservices.usgs.gov/nwis/site?sites=01013500&siteOutput=Expanded&format=rdb

returns
```
USGS 01013500 ... NAD83
```
for the field `coord_datum_cd  -- Latitude-longitude datum`.
So EPSG:4269 -- NAD83 is the correct crs.

There is room for discussion if NAD83 vs WGS 84 really matters in the
conterminous US however for Alaska errors in both the x and y direction
can be upwards of 1 meter in either direction.

BREAKING CHANGE: v1.0.10 is the only affected version. The GeoDataFrames
returned from the following functions now correctly have a crs of
EPSG:4269.
dataretrieval.nwis.get_qwdata
dataretrieval.nwis.get_discharge_measurements
dataretrieval.nwis.get_discharge_peaks
dataretrieval.nwis.get_gwlevels
dataretrieval.nwis.get_stats
dataretrieval.nwis.get_info
dataretrieval.nwis.get_pmcodes
dataretrieval.nwis.get_water_use
dataretrieval.nwis.get_ratings
dataretrieval.nwis.what_sites
dataretrieval.nwis.get_dv
dataretrieval.nwis.get_iv

dataretrieval/nwis.py

@@ -44,7 +44,8 @@
     "water_use",
     "ratings",
 ]
-_CRS = "EPSG:4236"
+# NAD83
+_CRS = "EPSG:4269"
 
 
 def format_response(