vim-patch:9.1.0278: filetype: zathurarc files not recognized

Problem:  filetype: zathurarc files not recognized
Solution: Detect '.zathurarc' files as zathurarc filetype,
          add zathurarc filetype (Wu, Zhenyu)

closes: vim/vim#14380

72d81a66ed

Co-authored-by: Wu, Zhenyu <wuzhenyu@ustc.edu>

runtime/lua/vim/filetype.lua

@@ -1578,6 +1578,7 @@ local filename = {
   ['.clang-format'] = 'yaml',
   ['.clang-tidy'] = 'yaml',
   ['yarn.lock'] = 'yaml',
+  zathurarc = 'zathurarc',
   ['/etc/zprofile'] = 'zsh',
   ['.zlogin'] = 'zsh',
   ['.zlogout'] = 'zsh',