Add -b flags to insert a window before (like the existing -a for after)

to break-pane, move-window, new-window. GitHub issue 2261.

tmux.1

@@ -1792,7 +1792,7 @@ from which the layout was originally defined.
 Commands related to windows and panes are as follows:
 .Bl -tag -width Ds
 .It Xo Ic break-pane
-.Op Fl adP
+.Op Fl abdP
 .Op Fl F Ar format
 .Op Fl n Ar window-name
 .Op Fl s Ar src-pane
@@ -1804,9 +1804,11 @@ Break
 off from its containing window to make it the only pane in
 .Ar dst-window .
 With
-.Fl a ,
-the window is moved to the next index up (following windows
-are moved if necessary).
+.Fl a
+or
+.Fl b ,
+the window is moved to the next index after or before (existing windows are
+moved if necessary).
 If
 .Fl d
 is given, the new window does not become the current window.
@@ -2188,7 +2190,7 @@ If no
 .Ar target-session
 is specified, select the last window of the current session.
 .It Xo Ic link-window
-.Op Fl adk
+.Op Fl abdk
 .Op Fl s Ar src-window
 .Op Fl t Ar dst-window
 .Xc
@@ -2203,9 +2205,12 @@ is specified and no such window exists, the
 .Ar src-window
 is linked there.
 With
-.Fl a ,
-the window is moved to the next index up (following windows
-are moved if necessary).
+.Fl a
+or
+.Fl b
+the window is moved to the next index after or before
+.Ar dst-window
+(existing windows are moved if necessary).
 If
 .Fl k
 is given and
@@ -2272,7 +2277,7 @@ section.
 Does the same as
 .Ic join-pane .
 .It Xo Ic move-window
-.Op Fl ardk
+.Op Fl abrdk
 .Op Fl s Ar src-window
 .Op Fl t Ar dst-window
 .Xc
@@ -2290,7 +2295,7 @@ the
 .Ic base-index
 option.
 .It Xo Ic new-window
-.Op Fl adkP
+.Op Fl abdkP
 .Op Fl c Ar start-directory
 .Op Fl e Ar environment
 .Op Fl F Ar format
@@ -2301,10 +2306,12 @@ option.
 .D1 (alias: Ic neww )
 Create a new window.
 With
-.Fl a ,
-the new window is inserted at the next index up from the specified
+.Fl a
+or
+.Fl b ,
+the new window is inserted at the next index after or before the specified
 .Ar target-window ,
-moving windows up if necessary,
+moving windows up if necessary;
 otherwise
 .Ar target-window
 is the new window location.