Small update for readme and changelog (#287)

Replace known issue with dialyzer cpu usage

Author: axelson

CHANGELOG.md

@@ -18,6 +18,7 @@ Changes:
 Bug Fixes:
 - Formatting was returning invalid floating point number (thanks [Thanabodee Charoenpiriyakij](https://github.com/wingyplus)) [#250](https://github.com/elixir-lsp/elixir-ls/pull/250)
 - Fix detection of empty hover hints (thanks [Dmitry Gutov](https://github.com/dgutov)) [#279](https://github.com/elixir-lsp/elixir-ls/pull/279)
+- Debugger doesn't fail when modules cannot be interpretted (thanks [Łukasz Samson](https://github.com/lukaszsamson)) (such as nifs) [#283](https://github.com/elixir-lsp/elixir-ls/pull/283)
 
 House keeping:
 - Server runs with a unique id (and uses it to disambiguate commands) (thanks [Alessandro Tagliapietra](https://github.com/alex88)) [#278](https://github.com/elixir-lsp/elixir-ls/pull/278)

README.md

@@ -157,7 +157,8 @@ and you installed Elixir and Erlang from the Erlang Solutions repository, you ma
 * Debugger doesn't work in Elixir 1.10.0 - 1.10.2 (but it should work in 1.10.3 when [this fix](https://github.com/elixir-lang/elixir/pull/9864) is released)
 * "Go to definition" does not work within the `scope` of a Phoenix router
 * On-hover docs do not work with erlang modules or functions (better support of EEP-48 is needed)
-* "Find references" does not work on Elixir 1.10.x [#257](https://github.com/elixir-lsp/elixir-ls/issues/257)
+* On first launch dialyzer will cause high CPU usage for a considerable time
+  * Possible mitigation in [#96](https://github.com/elixir-lsp/elixir-ls/issues/96)
 
 ## Building and running