Add ability to style RSS feed

[cowtrix]

RSS feeds are able to be styled with the <?xml-stylesheet type="text/css" href="rss-style.css" ?> sort of xml meta tag. Unfortunately it doesn't seem like there is any way to specify such a stylesheet right now for rss feeds using this package.

[markidox]

Possible solution created. This will apply a simple stylesheet and layout that matches the default cloudscribe theme.

[markidox]

I've made a further update to this to ensure it works in both scenarios (when used from the template and if pulled directly into a project).
There's a check in there to see if the xsl and css files already exist, if so they are NOT copied (this is to allow users to make changes to these files as they see fit).

However, that causes issues should we need to update those files in the future, a few options are:

1. Add a .v2. to the filenames, users would then have to decide whether to incorporate any changes we've made into their files and rename their files accordingly. But this ensure we wouldn't overwrite any changes they may have done.
2. We can add something in the csproj file that users can decide whether they are happy for files to be overwritten or not.

[JimKerslake]

Bit of documentation to explain the above:

[JimKerslake]

[JimKerslake]

There was no documentation on Syndication whatsoever, so...
https://www.cloudscribe.com/cloudscribesyndication
:)