Update "Mirros and nightly builds" section in "Install" (#1769)

Author: wojtekmach

install.markdown

@@ -159,7 +159,7 @@ Once you download the release, unpack it, and you are ready to run the `elixir`
 
 ### Mirrors and nightly builds
 
-The links above point directly to the GitHub release. We also host and mirror precompiled packages and nightly builds globally via `repo.hex.pm` using the following URL scheme:
+The links above point directly to the GitHub release. We also host and mirror precompiled packages and nightly builds globally via `builds.hex.pm` using the following URL scheme:
 
     https://builds.hex.pm/builds/elixir/${ELIXIR_VERSION}-otp-${OTP_VERSION}.zip
 
@@ -171,6 +171,10 @@ To use nightly for a given Erlang/OTP version (such as 25), use:
 
     https://builds.hex.pm/builds/elixir/main-otp-25.zip
 
+For a list of all builds, use:
+
+    https://builds.hex.pm/builds/elixir/builds.txt
+
 ## Compiling from source
 
 You can download and compile Elixir in few steps. The first one is to [install Erlang](/install.html#installing-erlang). You will also need [make](https://www.gnu.org/software/make/) available.