[readme] neovim version prerequisite added

Author: paulshuker

README.md

@@ -15,6 +15,8 @@ rely on the LSP (it is stand-alone). But, it can still reformat single-line code
 
 ## Install
 
+Neovim >= 0.5.0 is required.
+
 With [lazy.nvim](https://github.com/folke/lazy.nvim),
 
 ```lua

plugin/textangle.lua

@@ -1,5 +1,5 @@
 local VERSION_REQUIRED = "nvim-0.5.0"
 
 if vim.fn.has(VERSION_REQUIRED) ~= 1 then
-   vim.api.nvim_err_writeln("Example.nvim requires at least " .. VERSION_REQUIRED)
+   vim.api.nvim_err_writeln("textangle.nvim requires at least " .. VERSION_REQUIRED)
 end