Fix spelling (#1340)

Author: jawn

docs/index.md

@@ -24,7 +24,7 @@ Note: to get the latest pre-release build, add ` -Pre` to the end of the command
 
 Primary changes:
 
-- remove the System.Data.SqlClient depenency, allowing consumers to use System.Data.SqlClient or Microsoft.Data.SqlClient (or neither, or both) as they choose
+- remove the System.Data.SqlClient dependency, allowing consumers to use System.Data.SqlClient or Microsoft.Data.SqlClient (or neither, or both) as they choose
  - this means that some users may need to *re-add* one of the above as a `<PackageReference>` for their project to build, if they were previously relying on Dapper to provide System.Data.SqlClient
  - the `AsTableValuedParameter(this IEnumerable<SqlDataRecord>)` extension method is now `AsTableValuedParameter<T>(this IEnumerable<T>) where T : IDataRecord`; this is a breaking change but should be code-compatible and just requires a rebuild
 - unify the target platform at NetStandard2.0 (and .NET Framework 4.6.2 for the EF DB geometry/geography types)