docs: update todo and backup current config.rb

TODO.md

@@ -1,6 +1,8 @@
 - [x] add option to highlight trailing whitespace (off by default)
 - [x] add option to put characters at certain whitespace characters (off by default)
 	- whitespace kind -> character map should be configurable.
+- [ ] add option to insert spaces instead tab character when pressing tab:
+	- number of spaces should be configurable (per language)
 - [ ] diff view - design question:
 	- is it possible to angle the hatchings for empty lines more?
 	- if a character like the current one exists with a 45degree angle instead (and a top and bottom), we could use that across two columns. that would give us a perfectly 45 degree hatching.

config.backup.rb

@@ -0,0 +1,42 @@
+Vamp.configure do |config|
+  config.lsp.merge!(
+    "rust" => true,
+    "ruby" => true,
+    "python" => true,
+  )
+
+  # 0 (default): scroll only at viewport edges
+  # nil: center; oversized integer margins also center
+  config.scroll_distance = 7
+
+  config.highlight_trailing_whitespace = true
+
+  config.whitespace_scope = "leading" # or "all" (default)
+  config.whitespace_characters = {
+    " " => "·",
+    "\t" => "→",
+    "\n" => "↵",
+  }
+
+  # "bar" (default), "symbols", "line_numbers", "none"
+  config.git_gutter = "bar"
+
+  # diff view
+  config.diff_context_lines = 10
+  config.diff_expand_lines = 15
+
+  # general bindings
+  config.bind "leader q", config.core.pane.close
+  config.bind "leader t w", config.core.word_wrap.toggle
+
+  # pane navigation
+  config.bind "ctrl+w h", config.core.pane.focus_left
+  config.bind "ctrl+w j", config.core.pane.focus_down
+  config.bind "ctrl+w k", config.core.pane.focus_up
+  config.bind "ctrl+w l", config.core.pane.focus_right
+
+  # lsp bindings
+  config.bind "K", config.core.lsp.hover
+  config.bind "leader d", config.core.lsp.definition
+  config.bind "leader D", config.core.lsp.diagnostics
+end