doc: add document about folding range feature

Author: tomoto

README.md

@@ -61,6 +61,9 @@ and [Emacs](https://fortls.fortran-lang.org/editor_integration.html#emacs).
 - Code actions
   - Generate type-bound procedures and implementation templates for
     deferred procedures
+- Folding ranges
+  - Detect folding ranges based on Fortran syntax or indent as well as
+    consecutive comment lines
 
 ### Notes/Limitations
 
@@ -150,6 +153,7 @@ An example for a Configuration file is given below
 | `textDocument/didClose`          | Document synchronisation upon closing                  |
 | `textDocument/didChange`         | Document synchronisation upon changes to the document  |
 | `textDocument/codeAction`        | **Experimental** Generate code                         |
+| `textDocument/foldingRange       | Get folding ranges based on Fortran syntax and indent  |
 
 ## Future plans
 

docs/options.rst

@@ -76,7 +76,10 @@ All the ``fortls`` settings with their default arguments can be found below
 
       "symbol_skip_mem": false,
 
-      "enable_code_actions": false
+      "enable_code_actions": false,
+
+      "folding_range_mode": "indent",
+      "folding_range_comment_lines": 3
    }
 
 Sources file parsing

fortls/folding_ranges.py

@@ -22,7 +22,7 @@ class FoldingRange(TypedDict, total=False):
 
 def get_folding_ranges_by_block_comment(file_obj: FortranFile, min_block_size: int):
     """
-    Get the folding ranges in this file based on the block comment
+    Get the folding ranges in the given file based on the block comment
 
     Returns
     -------
@@ -82,7 +82,7 @@ def finalize(self, max_line_index: int):
 
 def get_folding_ranges_by_indent(file_obj: FortranFile) -> list[FoldingRange]:
     """
-    Get the folding ranges in this file based on the indent
+    Get the folding ranges in the given file based on the indent
 
     Returns
     -------
@@ -174,7 +174,7 @@ def finalize(self, num_lines: int):
 
 def get_folding_ranges_by_syntax(file_obj: FortranFile) -> list[FoldingRange]:
     """
-    Get the folding ranges in this file based on the syntax
+    Get the folding ranges in the given file based on the syntax
 
     Returns
     -------