Update dataretrieval/samples.py

Co-authored-by: Joe Zemmels (he/him) <jzemmels@gmail.com>

Author: ehinman

dataretrieval/samples.py

@@ -3,7 +3,7 @@
 
 See https://api.waterdata.usgs.gov/samples-data/docs#/ for API reference
 
-Not sure about avilable site types, characteristics, state codes, or other
+Not sure about available site types, characteristics, state codes, or other
 input parameters? Check out the samples data code service API reference:
 https://api.waterdata.usgs.gov/samples-data/codeservice/docs