feat(vim): setup document highlighting and diagnostics on hover

Now when the editor is idle it will use the lsp to highlight other
references to the token under the cursor.

It will also show all the diagnostics in a popup like the lsp hover that
I manually use via <C-k>. This is helpful with long diagnostic messages
that run off the edge of the terminal when.

site-modules/core/files/vim/plugin/lsp.lua

@@ -83,3 +83,27 @@ vim.diagnostic.config({
     border = border
   }
 })
+
+vim.cmd([[set updatetime=1000]])
+vim.api.nvim_create_augroup("lsp_document_highlight", { clear = true })
+vim.api.nvim_create_autocmd({ "CursorHold", "CursorHoldI" }, {
+  callback = function ()
+    -- Highlight document symbles for every file type other erb files because
+    -- solargraph only supports textDocument/documentHighlight in rb files.
+    local file_type = vim.api.nvim_buf_get_option(0, "filetype")
+    if file_type ~= "eruby" then
+      vim.lsp.buf.document_highlight()
+    end
+
+    vim.diagnostic.open_float()
+  end,
+  group = "lsp_document_highlight",
+  desc = "Document Highlight",
+})
+vim.api.nvim_create_autocmd("CursorMoved", {
+  callback = function ()
+    vim.lsp.buf.clear_references()
+  end,
+  group = "lsp_document_highlight",
+  desc = "Clear All the References",
+})