update :help references

README.md

@@ -651,7 +651,7 @@ vim.wo.number = true -- same as vim.api.nvim_win_set_option(0, 'number', true)
 ```
 
 See also:
-- `:help lua-vim-internal-options`
+- `:help lua-vim-options`
 
 #### Caveats
 
@@ -736,6 +736,9 @@ To delete one of these variables, simply assign `nil` to it:
 vim.g.some_global_variable = nil
 ```
 
+See also:
+- `:help lua-vim-variables`
+
 #### Caveats
 
 Unlike options meta-accessors, you cannot specify a number for buffer/window/tabpage-scoped variables.

doc/nvim-lua-guide.txt

@@ -720,7 +720,7 @@ no number is given, the current buffer/window is used:
 <
 
 See also:
-- |lua-vim-internal-options|
+- |lua-vim-options|
 
 Caveats~
 
@@ -821,6 +821,9 @@ To delete one of these variables, simply assign `nil` to it:
     vim.g.some_global_variable = nil
 <
 
+See also:
+- |lua-vim-variables|
+
 Caveats~
 
 Unlike options meta-accessors, you cannot specify a number for