feat: use official prefix if known

fixes the problem of standard w3.org vocabularies (skos, rdf, rdfs, etc.)

owl2yams/__init__.py

 import subprocess
 import re
 import os
+import json
 from pathlib import Path
 import shutil
 from typing import Iterable, Optional, List, Dict, Tuple
@@ -31,6 +32,9 @@
     XSD.float: "Float",
 }
 
+with open(f"{here}/prefixes.json","r") as fobj:
+    PREFIXES = json.load(fobj)
+
 
 def fragment_from_uri(uri: str, titling=False) -> Optional[str]:
     if uri == OWL.Thing:
@@ -43,7 +47,11 @@
         # otherwise split with `/`
         fragment = url.path.split("/")[-1]
     prefix = ""
-    if url.hostname is not None:
+    # try to find prefix in list of prefixes
+    unfragmented_url = uri.rstrip(fragment)
+    if unfragmented_url in PREFIXES:
+        prefix = PREFIXES[unfragmented_url] + "_"
+    elif url.hostname is not None:
         prefix = url.hostname.replace("www.", "").replace(".", "_") + "_"
     if titling:
         prefix = prefix.title().replace("_", "")