Add several classifiers related to social media

There are a number of social media use cases for which ample code can be found, but there is no appropriate classifier. Consider that the most popular RSS python library (feedparser) uses "Text Processing :: Markup :: XML" as its classifier, which is hardly the right mental model for someone looking for RSS-related projects. And granary, which exists to translate between different social networks has no reasonable topic classifier at all. This commit also adds a few social-specific protocols to the Topic :: Internet classification.

Example projects that would benefit from this classification:

* https://pypi.org/project/granary/ (Many social media protocols)
* https://github.com/halcy/Mastodon.py (Mastodon)
* https://github.com/kurtmckee/feedparser (RSS)
* https://github.com/snarfed/bridgy-fed (ActivityPub, Bluesky)
* https://github.com/MarshalX/atproto (AT Proto)
* https://github.com/bookwyrm-social/bookwyrm (ActivityPub)
* https://github.com/ytdl-org/youtube-dl (YouTube)
* https://github.com/InstaPy/InstaPy (Instagram)

src/trove_classifiers/__init__.py

@@ -573,6 +573,15 @@
     "Topic :: Communications :: File Sharing :: Napster",
     "Topic :: Communications :: Ham Radio",
     "Topic :: Communications :: Internet Phone",
+    "Topic :: Communications :: Social Media",
+    "Topic :: Communications :: Social Media :: Bluesky",   
+    "Topic :: Communications :: Social Media :: Facebook",
+    "Topic :: Communications :: Social Media :: Instagram",
+    "Topic :: Communications :: Social Media :: Lemmy",
+    "Topic :: Communications :: Social Media :: Mastodon",
+    "Topic :: Communications :: Social Media :: Pixelfed",
+    "Topic :: Communications :: Social Media :: Twitter/X",
+    "Topic :: Communications :: Social Media :: YouTube",
     "Topic :: Communications :: Telephony",
     "Topic :: Communications :: Usenet News",
     "Topic :: Database",
@@ -643,6 +652,9 @@
     "Topic :: Games/Entertainment :: Turn Based Strategy",
     "Topic :: Home Automation",
     "Topic :: Internet",
+    "Topic :: Internet :: ActivityPub",
+    "Topic :: Internet :: ActivityStreams",
+    "Topic :: Internet :: AtProto",
     "Topic :: Internet :: File Transfer Protocol (FTP)",
     "Topic :: Internet :: Finger",
     "Topic :: Internet :: Log Analysis",
@@ -660,6 +672,7 @@
     "Topic :: Internet :: WWW/HTTP :: Dynamic Content :: Wiki",
     "Topic :: Internet :: WWW/HTTP :: HTTP Servers",
     "Topic :: Internet :: WWW/HTTP :: Indexing/Search",
+    "Topic :: Internet :: WWW/HTTP :: RSS",
     "Topic :: Internet :: WWW/HTTP :: Session",
     "Topic :: Internet :: WWW/HTTP :: Site Management",
     "Topic :: Internet :: WWW/HTTP :: Site Management :: Link Checking",