Latex: Two figures inside one with one global caption -- using minipages

\begin{figure}

\begin{minipage}{.5\linewidth}
\centering
\subfloat[]{\label{main:a}\includegraphics[scale=.5]{example-image-a}}
\end{minipage}%
\begin{minipage}{.5\linewidth}
\centering
\subfloat[]{\label{main:b}\includegraphics[scale=.5]{example-image-b}}
\end{minipage}\par\medskip