build ignore the _build-agent build directory

Agent-driven builds use a separate _build-agent dir to avoid clashing with a persistent watcher on the default _build. Keep its artifacts out of version control.

Commit
bb9e4dbd2b70edfec6ba4f132c4e227533d3f2c6
Author
Marius Peter <dev@marius-peter.com>
Author date
Committer
Marius Peter <dev@marius-peter.com>
Committer date
.gitignore
index bcdfae04..2de7d63a 100644..100644
@@ -1,5 +1,6 @@
1 1 # Dune build artifacts
2 2 _build/
3 Added: _build-agent/
3 4
4 5 # Local opam switch
5 6 _opam/