fix: reduce code background priority in nofile buffers

## Details

Default priority for extmarks will prevent most other highlights from
showing above the ones from this plugin. In most cases this is fine, but
in lsp signature help docs this ends up overwriting the active parameter
highlight. Active parameter highlights are set with a priority of
`vim.hl.priorities.user` which defaults to 200, so the new default on
nofile buffers is set just below at 175.

Author: MeanderingProgrammer

CHANGELOG.md

@@ -13,6 +13,8 @@
 
 - handle double width glyph checkboxes [#553](https://github.com/MeanderingProgrammer/render-markdown.nvim/issues/553)
   [f58c05f](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/f58c05f349d6e7650f4b40b0df1514400f0c10de)
+- link icons following long checkboxes [#564](https://github.com/MeanderingProgrammer/render-markdown.nvim/issues/564)
+  [b2b1353](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/b2b135347e299ffbf7f4123fb7811899b0c9f4b8)
 
 ### Collaborator Shoutouts
 

README.md

@@ -932,6 +932,7 @@ require('render-markdown').setup({
         buftype = {
             nofile = {
                 render_modes = true,
+                code = { priority = 175 },
                 padding = { highlight = 'NormalFloat' },
                 sign = { enabled = false },
             },

doc/render-markdown.txt

@@ -1,4 +1,4 @@
-*render-markdown.txt*      For NVIM v0.11.5      Last change: 2025 December 02
+*render-markdown.txt*      For NVIM v0.11.5      Last change: 2025 December 11
 
 ==============================================================================
 Table of Contents                          *render-markdown-table-of-contents*
@@ -998,6 +998,7 @@ Default Configuration ~
             buftype = {
                 nofile = {
                     render_modes = true,
+                    code = { priority = 175 },
                     padding = { highlight = 'NormalFloat' },
                     sign = { enabled = false },
                 },

lua/render-markdown/health.lua

@@ -6,7 +6,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '8.10.6'
+M.version = '8.10.7'
 
 function M.check()
     M.start('versions')

lua/render-markdown/settings.lua

@@ -1409,6 +1409,7 @@ M.overrides.default = {
     buftype = {
         nofile = {
             render_modes = true,
+            code = { priority = 175 },
             padding = { highlight = 'NormalFloat' },
             sign = { enabled = false },
         },

tests/util.lua

@@ -79,6 +79,7 @@ function M.highlight(kind)
     local priority ---@type integer?
     local highlight ---@type string
     if kind == 'code' then
+        priority = vim.bo.buftype == 'nofile' and 175 or nil
         highlight = 'RmCodeInline'
     elseif kind == 'inline' then
         highlight = 'RmInlineHighlight'
@@ -312,6 +313,7 @@ end
 function M.code.bg()
     ---@type vim.api.keyset.set_extmark
     return {
+        priority = vim.bo.buftype == 'nofile' and 175 or nil,
         hl_eol = true,
         hl_group = 'RmCode',
     }