fix: Ignore heading patterns in fenced code blocks

- Addresses issue #145
- Fixes folding and jump-to-section behavior
- If folding or jump-to-section is initiated with the cursor IN a code
  block, the behavior will occur in the code block itself (i.e. the
  cursor will jump to the next heading inside the code block, if there
  is one, or it will fold the section inside of the code block)

lua/mkdnflow/cursor.lua

@@ -144,16 +144,21 @@ local go_to_heading = function(anchor_text, reverse)
     -- Record which line we're on; chances are the link goes to something later,
     -- so we'll start looking from here onwards and then circle back to the beginning
     local position = vim.api.nvim_win_get_cursor(0)
-    local starting_row, continue = position[1], true
+    local starting_row, continue, in_fenced_code_block = position[1], true, false
     local row = (reverse and starting_row - 1) or starting_row + 1
     while continue do
         local line = (reverse and vim.api.nvim_buf_get_lines(0, row - 1, row, false))
             or vim.api.nvim_buf_get_lines(0, row - 1, row, false)
         -- If the line has contents, do the thing
         if line[1] then
+            -- Are we in a code block?
+            if string.find(line[1], "^```") then
+                -- Flip the truth value
+                in_fenced_code_block = not in_fenced_code_block
+            end
             -- Does the line start with a hash?
             local has_heading = string.find(line[1], '^#')
-            if has_heading then
+            if has_heading and not in_fenced_code_block then
                 if anchor_text == nil then
                     -- Send the cursor to the heading
                     vim.api.nvim_win_set_cursor(0, { row, 0 })
@@ -191,6 +196,7 @@ local go_to_heading = function(anchor_text, reverse)
             -- If the line does not have contents, start searching from the beginning
             if anchor_text ~= nil or wrap == true then
                 row = (reverse and vim.api.nvim_buf_line_count(0)) or 1
+                in_fenced_code_block = false
             else
                 continue = nil
                 local place = (reverse and 'beginning') or 'end'

lua/mkdnflow/folds.lua

@@ -31,12 +31,16 @@ local get_section_range = function(start_row)
         vim.api.nvim_buf_line_count(0)
     local heading_level = M.getHeadingLevel(line)
     if heading_level > 0 then
-        local continue = true
+        local continue, in_fenced_code_block = true, false
         local end_row = start_row + 1
         while continue do
             local next_line = vim.api.nvim_buf_get_lines(0, end_row - 1, end_row, false)
             if next_line[1] then
-                if M.getHeadingLevel(next_line[1]) <= heading_level then
+                if string.find(next_line[1], "^```") then
+                    -- Flip the truth value
+                    in_fenced_code_block = not in_fenced_code_block
+                end
+                if M.getHeadingLevel(next_line[1]) <= heading_level and not in_fenced_code_block then
                     continue = false
                 else
                     end_row = end_row + 1
@@ -53,10 +57,14 @@ end
 
 local get_nearest_heading = function()
     local row = vim.api.nvim_win_get_cursor(0)[1] - 1
-    local continue = true
+    local continue, in_fenced_code_block = true, false
     while continue and row > 0 do
         local prev_line = vim.api.nvim_buf_get_lines(0, row - 1, row, false)[1]
-        if M.getHeadingLevel(prev_line) < 99 then
+        if string.find(prev_line, "^```") then
+            -- Flip the truth value
+            in_fenced_code_block = not in_fenced_code_block
+        end
+        if M.getHeadingLevel(prev_line) < 99 and not in_fenced_code_block then
             continue = false
             return row
         else