website: Fix gem5 source link
This link was pointing towards the master branch. This is to be removed.
This link has been changed to stable.
diff --git a/_pages/documentation/general_docs/apis.md b/_pages/documentation/general_docs/apis.md
index d46df6e..a651221 100644
--- a/_pages/documentation/general_docs/apis.md
+++ b/_pages/documentation/general_docs/apis.md
@@ -47,7 +47,7 @@
http://doxygen.gem5.org/release/current/group__api__simobject.html). The
definitions of different API groups can be found in
[`src/doxygen/group_definitions.hh`](
-https://gem5.googlesource.com/public/gem5/+/refs/heads/master/src/doxygen/group_definitions.hh).
+https://gem5.googlesource.com/public/gem5/+/refs/heads/stable/src/doxygen/group_definitions.hh).
### Notes for developers
