artifact-url.txt: record latest CI tarball URL (build #1768147)

ober

920762f711e3254dddb613218d582de3daf32ca8

diff --git a/artifact-url.txt b/artifact-url.txt
new file mode 100644
index 0000000..2d56db9
--- /dev/null
+++ b/artifact-url.txt
@@ -0,0 +1 @@
+https://s3.sr.ht/builds.sr.ht/artifacts/~lisp/1768147/0dbb615aad960c3d/jerboa-browser-0.0.1-linux-x86_64.tar.gz