Add basic checkhealth support

Neovim can use this API to report errors to the user.

Author: vimpostor

lua/tpipeline/health.lua

@@ -0,0 +1,15 @@
+local M = {}
+
+M.check = function()
+	vim.health.report_start("tpipeline report")
+	local info = vim.fn['tpipeline#debug#info']()
+
+	ver = vim.version()
+	if vim.version.lt(ver, {0, 6, 0}) then
+		vim.health.report_error(string.format("Neovim version %d.%d is not supported, use 0.6 or higher", ver.major, ver.minor))
+	else
+		vim.health.report_ok("Neovim version is supported")
+	end
+end
+
+return M