Removed latex textsl
Removed latex textsl

Removed latex \textsl command causing rendering issues in docs

See also: #337

Unidata/MetPy,Unidata/MetPy,jrleeman/MetPy,ShawnMurd/MetPy,dopplershift/MetPy,dopplershift/MetPy,ahaberlie/MetPy,jrleeman/MetPy,ahaberlie/MetPy