markdown: adds the vim-markdown plugins

Co-Authored-by: iGor milhit <igor@milhit.ch>

after/ftplugin/markdown.lua

@@ -4,5 +4,5 @@
 
 -- vim.opt.foldmethod="expr"
 -- vim.opt.foldexpr="nvim_treesitter#foldexpr()"
-vim.g.markdown_folding=1
+-- vim.g.markdown_folding=1
 -- vim.opt.foldlevel=1

lua/custom/plugins/vim-markdown.lua

@@ -0,0 +1,19 @@
+-- Syntax highlighting, matching rules and mappings for the original Markdown
+-- and extensions.
+--   https://github.com/preservim/vim-Markdown
+
+-- Configure the folding style and folding level
+vim.cmd([[ let g:vim_markdown_folding_level = 1 ]])
+vim.cmd([[ let g:vim_markdown_folding_style_pythonic = 1 ]])
+
+-- Enable the YAML frontmatter support (no highlight yet?)
+vim.cmd([[ let g:vim_markdown_frontmatter = 1 ]])
+
+return {
+  {
+    "preservim/vim-markdown",
+    ft = {
+      'markdown'
+    }
+  }
+}