Added some missing file types to the documentation.

src/physfs.h

@@ -140,6 +140,8 @@
  *
  * Currently supported archive types:
  *   - .ZIP (pkZip/WinZip/Info-ZIP compatible)
+ *   - .7Z  (7zip archives)
+ *   - .ISO (ISO9660 files, CD-ROM images)
  *   - .GRP (Build Engine groupfile archives)
  *   - .PAK (Quake I/II archive format)
  *   - .HOG (Descent I/II HOG file archives)