Updates hydra: a3e8aa6 Feat: migrate docs to MkDocs

diff --git a/hydra b/hydra
index 4395ba1f645d36fa0a29e63f43d6a14e5c052372..a3e8aa6c319e38606e7d10562c793e3027c57ff4 160000 (submodule)
--- a/hydra
+++ b/hydra
@@ -1 +1 @@
-Subproject commit 4395ba1f645d36fa0a29e63f43d6a14e5c052372
+Subproject commit a3e8aa6c319e38606e7d10562c793e3027c57ff4