fix: a lot of small things and adds more customization for caret (#554)

Attention:
prompt_prefix will no longer add a space at the end. So if you still want a space at the end make sure your configuration has one.
The default should not be changed. So if you haven't copied prompt_prefix in your config this doesn't affect you.

Feat:
- prompt prefix does no longer always end with space
- selection_caret configurable. Default: `> `
- result_prefix configurable. Default: `  `
- more actions for git_branches
  - <c-t> does track the branch
  - <c-r> does rebase branch
  - also added delete branch action but not configured. See readme on how to do that

Fixes:
- fix docgen ci
- Better error for lsp_workspace_symbols
- better formatting for CONTRIBUTING.md
- move from systemlist to plenary.job
- git branch now supports checkout on remote branches

lua/telescope/config.lua

@@ -75,7 +75,21 @@ function config.set_defaults(defaults)
   set("results_height", 1)
   set("results_width", 0.8)
 
-  set("prompt_prefix", ">")
+  set("prompt_prefix", "> ", [[
+    Will be shown in front of the prompt.
+
+    Default: '> '
+  ]])
+  set("selection_caret", "> ", [[
+    Will be shown in front of the selection.
+
+    Default: '> '
+  ]])
+  set("entry_prefix", "  ", [[
+    Prefix in front of each result entry. Current selection not included.
+
+    Default: '  '
+  ]])
   set("initial_mode", "insert")
 
   set("border", {})