Refine EditorConfig glob spec

The glob spec of EditorConfig works in a non-intuitive way that is
different from glob of POSIX-compatible shells. The pattern matching is
done in the directory the target file is in instead of the EditorConfig
file in, like the '.gitignore' file. Therefore, simply 'foo' matches
'foo' in the root directory and each sub-directory, and '/foo' has to be
used to match the file in the root directory only.

See: editorconfig/editorconfig#283 (comment)
Change-Id: Iea6d25f2ba551db0420ed1fa968f0b355046cabf

Author: lumynou5

.editorconfig

@@ -10,15 +10,15 @@ indent_style = tab
 indent_size = 4
 max_line_length = 80
 
-[**/*.[ch]]
+[*.[ch]]
 indent_style = space
 indent_size = 4
 max_line_length = 80
 
-[{**/*.py,.ci/*}]
+[{*.py,/.ci/*}]
 indent_style = space
 indent_size = 4
 
-[{scripts/*,.github/workflows/*}]
+[{/scripts/*,/.github/workflows/*}]
 indent_style = space
 indent_size = 2