The title is more of a possible solution to my problem. But let's start with the problem first:

I have a markdown with unnecessary indententation like below:

# Heading 1
    - Content 1
        - Content 2
# Heading 2
    - Some Content

I want to remove the indentation in the content:

diff --git a/before b/after
index 711b728..dbbd285 100644
--- a/before
+++ b/after
@@ -1,6 +1,6 @@
 # Heading 1
-    - Content 1
-        - Content 2
+- Content 1
+    - Content 2
 # Heading 2
-    - Some Content
+- Some Content
 

I think I'm almost there, with the following pattern:

comby '#:[heading\n]:[content]#' '<rewrite_template>' markdown.md -matcher txt

Now the content is captured but I am not aware of any way to remove the indententation.

It would be great if there was already such a capability. But if not, the solution I'm thinking of is, to add support for something like nesting rewrite. That is, to allow the captured text (in this case, :[content]) to be processed by another comby command (in this case, the nesting command would replace leading tab/spaces at each line with an empty string).

What is your take?