infra: add sr.ht build script

.builds/openbsd.yml

@@ -0,0 +1,16 @@
+image: archlinux
+sources:
+  - https://github.com/mahkoh/jay
+tasks:
+  - install: |
+      sudo pacman -S rustup
+      rustup toolchain install stable
+      rustup default stable
+  - build: |
+      cd jay
+      cargo build --features it
+  - test: |
+      cd jay
+      export RUSTC_BOOTSTRAP=1
+      export RUST_BACKTRACE=1
+      cargo run --features it -- run-tests

.gitignore

@@ -1,5 +1,6 @@
 .*
 !.gitignore
 !/.cargo
+!/.builds
 /target
 /testruns