mappings: Allow to remove plugin mappings in chadrc

This enables us to disable a plugin mappings individually

for eg:
  M.mappings.plugins = {
      telelscope = {
          find_hiddenfiles = false
      }
  }

  This will disable the telelscope find_hiddenfiles mapping.

It's also helpful when we want to use the mapping used by find_hiddenfiles for something else

lua/core/default_config.lua

@@ -166,7 +166,7 @@ M.mappings = {
 }
 
 -- plugins related mappings
-
+-- To disable a mapping, equate the variable to "" or false or nil in chadrc
 M.mappings.plugins = {
    bufferline = {
       next_buffer = "<TAB>",