completion: add completion for text in the buffer

- Adds completion capabilities for text (in the current buffer), with
  the help of `cmp-buffer`).
- Set the keyword_length to 4 in order to lighten the buffer completion.
- Supports non ASCII chars in text completion (cmp-buffer).
- Restore the luasnip configuration inside the nvim-cmp configuration,
  as it is indeed closely related. I didn't understood it in the first
  place.
- Add a markdown snippet to add a tags line in my incremental notes
  (journal).
- Expand the French dictionnary.

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

init.lua

@@ -106,6 +106,9 @@ require('lazy').setup({
       -- Adds LSP completion capabilities
       'hrsh7th/cmp-nvim-lsp',
       
+      -- Adds completion capabilities for text in buffers
+      'hrsh7th/cmp-buffer',
+
       -- Adds path completion capabilities
       'hrsh7th/cmp-path',
 
@@ -531,7 +534,7 @@ mason_lspconfig.setup_handlers {
   end,
 }
 
--- [[ Configure nvim-cmp ]]
+-- [[ Configure nvim-cmp, and LuaSnip ]]
 -- See `:help cmp`
 local cmp = require 'cmp'
 local luasnip = require 'luasnip'
@@ -548,6 +551,10 @@ luasnip.config.setup {
 -- Load snippets from ~/.config/nvim/LuaSnip/
 require("luasnip.loaders.from_lua").load({paths = "~/.config/nvim/my_snippets/"})
 
+-- Keymap to reload snippets
+--   https://www.ejmastnak.com/tutorials/vim-latex/luasnip/#refreshing-snippets-from-a-separate-vim-instance
+vim.keymap.set('n', '<Leader>L', '<Cmd>lua require("luasnip.loaders.from_lua").load({paths = "~/.config/nvim/my_snippets/"})<CR>', { desc = 'Reload [L]uaSnippets' })
+
 cmp.setup {
   snippet = {
     expand = function(args)
@@ -585,6 +592,13 @@ cmp.setup {
   },
   sources = {
     { name = 'nvim_lsp' },
+    {
+      name = 'buffer',
+      option = {
+        keyword_length = 4,
+        keyword_pattern = [[\k\+]],
+      },
+    },
     { name = 'luasnip' },
     { name = 'path' },
   },

my_snippets/markdown.lua

@@ -147,5 +147,20 @@ return {
       },
       { repeat_duplicates = true }
     )
+  ),
+  s(
+    {
+      trig = "tags",
+      name = "Tags",
+      dscr = "Insert a one-line tags array, in a text file (markdown)."
+    },
+    fmt(
+      [[
+      tags: [{}]
+      ]],
+      {
+        i(1, "tags")
+      }
+    )
   )
 }