Add RSMViewer plugin for RNA structural motif visualization

[Rakib-Hasan-Rahad]

kindly Add RSMViewer plugin for RNA structural motif visualization to the plugin list.
https://github.com/Rakib-Hasan-Rahad/RSMViewer
Description:
Added the RSMViewer plugin, a visualization tool for exploring RNA Structural Motifs (RSMs). This plugin enables interactive viewing and analysis of RNA motif structures, supporting better interpretation of motif annotations and structural relationships.