feat(python): add semantic highlighting (#1149)

* feat(python): add semantic highlighting

* refactor: moved to python-semshi

---------

Co-authored-by: Folke Lemaitre <folke.lemaitre@gmail.com>

lua/lazyvim/plugins/extras/lang/python-semshi.lua

@@ -0,0 +1,31 @@
+return {
+  -- "numiras/semshi",
+  "wookayin/semshi", -- use a maintained fork
+  ft = "python",
+  build = ":UpdateRemotePlugins",
+  init = function()
+    -- Disabled these features better provided by LSP or other more general plugins
+    vim.g["semshi#error_sign"] = false
+    vim.g["semshi#simplify_markup"] = false
+    vim.g["semshi#mark_selected_nodes"] = false
+    vim.g["semshi#update_delay_factor"] = 0.001
+
+    -- This autocmd must be defined in init to take effect
+    vim.api.nvim_create_autocmd({ "VimEnter", "ColorScheme" }, {
+      group = vim.api.nvim_create_augroup("SemanticHighlight", {}),
+      callback = function()
+        -- Only add style, inherit or link to the LSP's colors
+        vim.cmd([[
+            highlight! semshiGlobal gui=italic
+            highlight! semshiImported gui=bold
+            highlight! link semshiParameter @lsp.type.parameter
+            highlight! link semshiParameterUnused DiagnosticUnnecessary
+            highlight! link semshiBuiltin @function.builtin
+            highlight! link semshiAttribute @attribute
+            highlight! link semshiSelf @lsp.type.selfKeyword
+            highlight! link semshiUnresolved @lsp.type.unresolvedReference
+            ]])
+      end,
+    })
+  end,
+}