Improve repository description

Please change

`Collection of tools allowing to React.js applications to run on specific server-side environments such as Content Management Systems (CMS) or Portals.`

to something like

`Collection of tools allowing easy integration of React.js applications into content management systems or enterprise portals.`

in the repository description. This fixes a grammar mistake and describes the project better in my opinion. (it also "has a better feel", because I'm a grammar nazi and a pedant).