Add list of fields in filesystem detail view

Belongs with #1051

Looks like:

       FIELDS for stratis filesystem list [(--uuid <uuid> |--name <name>)]

       UUID
           The UUID of the filesystem.

       Name
           The name of the filesystem.

       Pool
           The name of the filesystem’s pool.

       Device
           The device path to use for mounting the filesystem.

       Created
           The time the filesystem was created.

       Snapshot origin
           If this filesystem is a snapshot, its origin.

       Sizes
           The logical size of the Stratis filesystem, the total space
           actually used, and the logical amount free on the Stratis
           filesystem. Since every Stratis filesystem holds an XFS filesystem,
           a new Stratis filesystem will have a non-zero amount used for the
           XFS filesystem metadata.

Signed-off-by: mulhern <[email protected]>
(cherry picked from commit 799c791)

docs/stratis.txt

@@ -325,6 +325,34 @@ UUID::
 	  The UUID of the filesystem.
 
 
+FIELDS for stratis filesystem list [(--uuid <uuid> |--name <name>)]
+
+UUID::
+	The UUID of the filesystem.
+
+Name::
+	The name of the filesystem.
+
+Pool::
+	The name of the filesystem's pool.
+
+Device::
+	The device path to use for mounting the filesystem.
+
+Created::
+	The time the filesystem was created.
+
+Snapshot origin::
+	If this filesystem is a snapshot, its origin.
+
+Sizes::
+	The logical size of the Stratis filesystem, the total space actually
+	used, and the logical amount free on the Stratis filesystem. Since
+	every Stratis filesystem holds an XFS filesystem, a new Stratis
+	filesystem will have a non-zero amount used for the XFS filesystem
+	metadata.
+
+
 FIELDS for stratis blockdev list
 
 Pool Name::