ci: added simple ci, improved readme

.github/workflows/test.yml

@@ -0,0 +1,30 @@
+name: test
+
+on:
+  push:
+    branches:
+      - dev
+
+env:
+  CARGO_TERM_COLOR: always
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        toolchain:
+          - stable
+          - beta
+          - nightly
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.toolchain }}
+      - run: cargo build --verbose
+      - run: cargo test --verbose

README.md

@@ -1,4 +1,9 @@
 # jni-toolbox
+[![Actions Status](https://github.com/hexedtech/jni-toolbox/actions/workflows/test.yml/badge.svg)](https://github.com/hexedtech/jni-toolbox/actions)
+[![Crates.io Version](https://img.shields.io/crates/v/jni-toolbox)](https://crates.io/crates/jni-toolbox)
+[![docs.rs](https://img.shields.io/docsrs/jni-toolbox)](https://docs.rs/jni-toolbox)
+
+
 this is a simple crate built around [jni-rs](https://github.com/jni-rs/jni-rs) to automatically generate JNI-compatible extern functions
 
 it also wraps functions returning `Result<>`, making short-circuiting easy