btrfs-progs: docs: convert btrfs-find-root to rst

Signed-off-by: David Sterba <dsterba@suse.com>

Documentation/btrfs-find-root.rst

@@ -0,0 +1,36 @@
+btrfs-find-root(8)
+==================
+
+SYNOPSIS
+--------
+
+**btrfs-find-root** [options] <device>
+
+DESCRIPTION
+-----------
+
+**btrfs-find-root** is used to find the satisfied root, you can filter by
+root tree's objectid, generation, level.
+
+OPTIONS
+-------
+
+-a
+        Search through all metadata extents, even the root has been already found.
+-g <generation>
+        Filter root tree by it's original transaction id, tree root's generation in default.
+-o <objectid>
+        Filter root tree by it's objectid,tree root's objectid in default.
+-l <level>
+        Filter root tree by b-tree's level, level 0 in default.
+
+EXIT STATUS
+-----------
+
+**btrfs-find-root** will return 0 if no error happened.
+If any problems happened, 1 will be returned.
+
+SEE ALSO
+--------
+
+``mkfs.btrfs(8)``

Documentation/conf.py

@@ -54,4 +54,5 @@ man_pages = [
     ('btrfs-property', 'btrfs-property', 'get/set/list properties for given filesystem object', '', 8),
     ('btrfs-inspect-internal', 'btrfs-inspect-internal', 'query various internal information', '', 8),
     ('btrfs-image', 'btrfs-image', 'create/restore an image of the filesystem', '', 8),
+    ('btrfs-find-root', 'btrfs-find-root', 'filter to find btrfs root', '', 8),
 ]

Documentation/man-index.rst

@@ -6,6 +6,7 @@ Manual pages
 .. toctree::
    :maxdepth: 1
 
+   btrfs-find-root
    btrfs-image
    btrfs-inspect-internal
    btrfs-property