feat(projectmanager): support project_non_root option

the RootchandgeCallback function should only be
called on project.

docs/documentation.md

@@ -2012,6 +2012,26 @@ For example, to ignore the `node_packages/` directory:
     project_rooter_outermost = false
 ```
 
+There are three options for non-project files/directories:
+
+- Don't change directory (default).
+
+```
+project_non_root = ''
+```
+
+- Change to file's directory (similar to 'autochdir').
+
+```
+project_non_root = 'current'
+```
+
+- Change to home directory.
+
+```
+project_non_root = 'home'
+```
+
 You can also disable project root detection completely (i.e. vim will set the
 root directory to the present working directory):
 
@@ -2385,7 +2405,7 @@ The default color for iedit is `red`/`green` which is based on the current color
 
 SpaceVim provides an asynchronous code runner plugin. In most language layers,
 the key binding `SPC l r` is defined for running the current buffer.
-To close the code runner windows, you can use ``Ctrl-` `` key binding.
+To close the code runner windows, you can use `` Ctrl-`  `` key binding.
 If you need to add new commands, you can use the bootstrap function. For example:
 Use `F5` to build the project asynchronously.
 
@@ -2400,7 +2420,6 @@ Key bindings within code runner buffer:
 | `ctrl-c`    | stop code runner            |
 | `i`         | open promote to insert text |
 
-
 #### Custom runner
 
 If you want to set custom code runner for specific language. You need to use `SpaceVim#plugins#runner#reg_runner(ft, runner)` api in bootstrap function.

lua/spacevim/plugin/projectmanager.lua

@@ -383,13 +383,30 @@ function M.current_root()
   if rootdir == '' then
     rootdir = find_root_directory()
     if rootdir == nil or rootdir == '' then
-      rootdir = sp_file.unify_path(fn.getcwd())
+      -- for no project
+      if vim.g.spacevim_project_non_root == '' then
+        rootdir = sp_file.unify_path(fn.getcwd())
+      elseif vim.g.spacevim_project_non_root == 'home' and filereadable(bufname) then
+        rootdir = sp_file.unify_path(fn.expand('~'))
+      elseif vim.g.spacevim_project_non_root == 'current' then
+        local dir = sp_file.unify_path(bufname, ':p:h')
+        if isdirectory(dir) then
+          rootdir = dir
+        else
+          rootdir = sp_file.unify_path(fn.getcwd())
+        end
+      else
+        -- maybe log error
+      end
+      change_dir(rootdir)
+    else
+      -- for project
+      if change_dir(rootdir) then
+        M.RootchandgeCallback()
+      end
     end
     fn.setbufvar('%', 'rootDir', rootdir)
   end
-  if change_dir(rootdir) then
-    M.RootchandgeCallback()
-  end
   return rootdir
 end