Move properties, parameters, events, and concepts around manual sections

The pages moved as follows:
  zpool-features.{5 => 7}
  spl{-module-parameters.5 => .4}
  zfs{-module-parameters.5 => .4}
  zfs-events.5 => into zpool-events.8
  zfsconcepts.{8 => 7}
  zfsprops.{8 => 7}
  zpoolconcepts.{8 => 7}
  zpoolprops.{8 => 7}

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Co-authored-by: Daniel Ebdrup Jensen <debdrup@FreeBSD.org>
Closes #12149
Closes #12212

man/man8/zfs-set.8

@@ -65,7 +65,7 @@
 .Xc
 Only some properties can be edited.
 See
-.Xr zfsprops 8
+.Xr zfsprops 7
 for more information on what properties can be set and acceptable
 values.
 Numeric values can be specified as exact values, or in a human-readable form
@@ -78,7 +78,7 @@ User properties can be set on snapshots.
 For more information, see the
 .Em User Properties
 section of
-.Xr zfsprops 8 .
+.Xr zfsprops 7 .
 .It Xo
 .Nm zfs
 .Cm get
@@ -114,7 +114,7 @@ This command takes a comma-separated list of properties as described in the
 and
 .Sx User Properties
 sections of
-.Xr zfsprops 8 .
+.Xr zfsprops 7 .
 .Pp
 The value
 .Sy all
@@ -163,7 +163,7 @@ restored to default if no ancestor has the property set, or with the
 .Fl S
 option reverted to the received value if one exists.
 See
-.Xr zfsprops 8
+.Xr zfsprops 7
 for a listing of default values, and details on which properties can be
 inherited.
 .Bl -tag -width "-r"
@@ -178,5 +178,5 @@ option was not specified.
 .El
 .
 .Sh SEE ALSO
-.Xr zfs-list 8 ,
-.Xr zfsprops 8
+.Xr zfsprops 7 ,
+.Xr zfs-list 8