Add jsonnet formatting (if jsonnet is installed)

contrib/ci/drone-format-verify.sh

@@ -2,4 +2,5 @@
 test "x$IGNORE" != "x" && exit 0
 repo=$(readlink -e $(dirname $0)/../../)
 clang-format-11 -i $(find $repo/jni $repo/daemon $repo/llarp $repo/include $repo/pybind | grep -E '\.[hc](pp)?$')
+jsonnetfmt -i $repo/.drone.jsonnet
 git --no-pager diff --exit-code --color || (echo -ne '\n\n\e[31;1mLint check failed; please run ./contrib/format.sh\e[0m\n\n' ; exit 1)

contrib/format.sh

@@ -41,3 +41,14 @@ if [ $? -eq 0 ]; then
     fi
 
 fi
+
+jsonnet_format=$(command -v jsonnetfmt 2>/dev/null)
+if [ $? -eq 0 ]; then
+    if [ "$1" = "verify" ]; then
+        if ! $jsonnet_format --test .drone.jsonnet; then
+            exit 4
+        fi
+    else
+        $jsonnet_format --in-place .drone.jsonnet
+    fi
+fi