feat: add mapping and docs for order_by_git_status

Author: cseickel

README.md

@@ -339,6 +339,7 @@ use {
               ["o"] = { "show_help", nowait=false, config = { title = "Order by", prefix_key = "o" }},
               ["oc"] = { "order_by_created", nowait = false },
               ["od"] = { "order_by_diagnostics", nowait = false },
+              ["og"] = { "order_by_git_status", nowait = false },
               ["om"] = { "order_by_modified", nowait = false },
               ["on"] = { "order_by_name", nowait = false },
               ["os"] = { "order_by_size", nowait = false },

doc/neo-tree.txt

@@ -305,6 +305,8 @@ oc = ...created:     Sort the tree by created date.
 
 od = ...diagnostics: Sort by diagnostic severity.
 
+og = ...git_status:  Sort by git status.
+
 om = ...modified:    Sort by last modified date.
 
 om = ...name:        Sort by name (default sort).

lua/neo-tree/defaults.lua

@@ -418,6 +418,7 @@ local config = {
         ["o"] = { "show_help", nowait=false, config = { title = "Order by", prefix_key = "o" }},
         ["oc"] = { "order_by_created", nowait = false },
         ["od"] = { "order_by_diagnostics", nowait = false },
+        ["og"] = { "order_by_git_status", nowait = false },
         ["om"] = { "order_by_modified", nowait = false },
         ["on"] = { "order_by_name", nowait = false },
         ["os"] = { "order_by_size", nowait = false },