readme: cosmetic changes + pipeline update

Signed-off-by: Alexandra Iordache <aghecen@amazon.com>

Author: Alexandra Iordache

README.md

@@ -24,31 +24,34 @@ Each individual test runs in a container. To reproduce a test locally, you can
 use the dev-container on both x86 and arm64.
 
 ```bash
+container_version=5
 docker run -it \
            --security-opt seccomp=unconfined \
            --volume $(pwd):/linux-loader \
-           rustvmm/dev:v2
+           rustvmm/dev:v${container_version}
 cd linux-loader/
 cargo test
 ```
 
 ### bzImage test
 
-As we don't want to distribute an entire kernel bzImage, the `load_bzImage` test is ignored by
-default. In order to test the bzImage support, one needs to locally build a bzImage, copy it
-to the `src/loader` directory and run cargo test:
-
-```shell
-# Assuming your linux-loader and linux-stable are both under $LINUX_LOADER
-$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git $LINUX_LOADER/linux-stable
-$ cd linux-stable
-$ make bzImage 
-$ cp linux-stable/arch/x86/boot/bzImage $LINUX_LOADER/linux-loader/src/loader/
-$ cd $LINUX_LOADER/linux-loader
-$ docker run -it \
+As we don't want to distribute an entire kernel bzImage, the `load_bzImage`
+test is ignored by default. In order to test the bzImage support, one needs to
+locally build a bzImage, copy it to the `src/loader` directory and run
+`cargo test`:
+
+```bash
+# Assuming your linux-loader and linux-stable are both under ${LINUX_LOADER}:
+git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ${LINUX_LOADER}/linux-stable
+cd linux-stable
+make bzImage 
+cp linux-stable/arch/x86/boot/bzImage ${LINUX_LOADER}/linux-loader/src/loader/
+cd ${LINUX_LOADER}/linux-loader
+container_version=5
+docker run -it \
            --security-opt seccomp=unconfined \
            --volume $(pwd):/linux-loader \
-           rustvmm/dev:v2
-$ cd linux-loader/
-$ cargo test 
+           rustvmm/dev:v${container_version}
+cd linux-loader/
+cargo test 
 ```