update readme

Author: lukaszsamson

README.md

@@ -103,13 +103,14 @@ If you access any projects via symlinks, and the lsp crashes immediately on star
 
 ## Supported Elixir and OTP versions
 
-Elixir itself supports five versions with security updates:
+Elixir itself supports the last five released versions with security updates:
 https://hexdocs.pm/elixir/compatibility-and-deprecations.html#content
 
-OTP supports the last three versions:
-https://www.erlang.org/doc/system/misc.html
+OTP supports the last three versions with security updates:
+https://github.com/erlang/otp/blob/master/SECURITY.md#supported-versions
+https://www.erlang.org/doc/system/misc.html#supported-releases
 
-ElixirLS generally aims to support the last three released versions of Elixir and the last three versions of OTP. However this is not a hard and fast rule and may change in the future.
+ElixirLS generally aims to support all supported versions of Elixir on all compatible versions of OTP. However this is not a hard and fast rule and may change in the future.
 
 ### Support matrix