patch 8.2.3022: available encryption methods are not strong enough

Problem:    Available encryption methods are not strong enough.
Solution:   Add initial support for xchaha20. (Christian Brabandt,
            closes #8394)
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index dd2d242..4620623 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -11971,6 +11971,7 @@
 showcmd			Compiled with 'showcmd' support.
 signs			Compiled with |:sign| support.
 smartindent		Compiled with 'smartindent' support.
+sodium			Compiled with libsodium for better crypt support
 sound			Compiled with sound support, e.g. `sound_playevent()`
 spell			Compiled with spell checking support |spell|.
 startuptime		Compiled with |--startuptime| support.