bug#51138: Increase the value of kill-ring-max

[Juri Linkov]

>> >  (defcustom yank-menu-length 20
>> > -  "Maximum length to display in the `yank-menu'."
>> > +  "Maximum length of entries in the `yank-menu'."
>>
>> The previous docstring was unclear, but the new docstring
>> doesn't make it clearer.  I don't have a concrete suggestion,
>> but it needs to say that this length truncates the text
>> of each menu item.
>
> How about "Items in `yank-menu' longer than this will be truncated."?

"Maximum length to which entries in the 'yank-menu' will be truncated."
suggested by Stefan and your suggestion will make the docstring much clearer.