feat: allow number and relativenumber settings (#762)

README.md

@@ -88,7 +88,9 @@ require'nvim-tree'.setup {
     mappings = {
       custom_only = false,
       list = {}
-    }
+    },
+    number = false,
+    relativenumber = false
   }
 }
 ```

doc/nvim-tree-lua.txt

@@ -110,14 +110,16 @@ function.
         height = 30,
         side = 'left',
         auto_resize = false,
+        number = false,
+        relativenumber = false,
         mappings = {
           custom_only = false,
           list = {}
         }
       },
       filters = {
-	dotfiles = false,
-	custom = {}
+        dotfiles = false,
+        custom = {}
       }
     }
 <
@@ -287,6 +289,16 @@ Here is a list of the options available in the setup call:
       type: `boolean`
       default: false
 
+  - |view.number|: print the line number in front of each line.
+      type: `boolean`
+      default: false
+
+  - |view.relativenumber|: show the line number relative to the line with the
+    cursor in front of each line. If the option `view.number` is also `true`,
+    the number on the cursor line will be the line number instead of `0`.
+      type: `boolean`
+      default: false
+
   - |view.mappings|: configuration options for keymaps
 
     - |view.mappings.custom_only|: will use only the provided user mappings and not the default

lua/nvim-tree/view.lua

@@ -114,7 +114,9 @@ local DEFAULT_CONFIG = {
   mappings = {
     custom_only = false,
     list = {}
-  }
+  },
+  number = false,
+  relativenumber = false
 }
 
 local function merge_mappings(user_mappings)
@@ -147,6 +149,8 @@ function M.setup(opts)
   M.View.height = options.height
   M.View.hide_root_folder = options.hide_root_folder
   M.View.auto_resize = opts.auto_resize
+  M.View.winopts.number = options.number
+  M.View.winopts.relativenumber = options.relativenumber
   if options.mappings.custom_only then
     M.View.mappings = options.mappings.list
   else