fix(fold): don't include whitespace end regions

Some languages that are difficult to parse via Treesitter may
incorrectly include whitespace lines at the end of regions. This can
makes the calculated folds sub-optimal.

To recitfy, use a custom directive (trim), to calculate the range with
the trailing whitespace lines removed. Note this only works if the
region end column is 0.

Also added folds for Make.

queries/make/folds.scm

@@ -0,0 +1,7 @@
+(
+  [
+    (conditional)
+    (rule)
+  ] @fold
+  (#trim! @fold)
+)

queries/markdown/folds.scm

@@ -1,6 +1,9 @@
-[
-  (fenced_code_block)
-  (indented_code_block)
-  (list)
-  (section)
-] @fold
+(
+  [
+    (fenced_code_block)
+    (indented_code_block)
+    (list)
+    (section)
+  ] @fold
+  (#trim! @fold)
+)