fix README.md for Ubuntu24 docker

tools/rocm-build/docker/ubuntu24/README.md

@@ -1,18 +1,27 @@
 ## Steps to build the Docker Image
+
 1. Clone this repositry
+
    ```bash
    git clone https://github.com/ROCm/rocm-build.git
    ```
+
 2. Go into the OS specific docker directory in build-infra
+
     ```bash
     cd rocm-build/build/docker/ubuntu24
     ```
+
 3. Build the docker image
+
     ```bash
     docker build -t <docker Image Name> .
     ```
+
     replace the `<docker Image Name>` with the new Docker image Name of your choice,
+
 4. After successful build, verify your \<docker Image Name\> in the list all available docker images.
+
     ```bash
     docker images
     ```