Update README files to include installation instructions for ffmpeg and Java on the Coder platform

Author: aravind-3105

implementations/multimedia_rag/README.md

@@ -89,12 +89,22 @@ Two independent environments are required due to package conflicts between the R
 
 ---
 
+> **On the Coder platform**, `ffmpeg` is already available. You can verify with:
+>
+> ```bash
+> ffmpeg -version
+> ```
+
+<details>
+<summary>Not on Coder? Install ffmpeg manually</summary>
+
 ```bash
-# If ffmpeg is not installed, install it for video/audio processing
 sudo apt update
 sudo apt install ffmpeg
 ```
 
+</details>
+
 Both the retrieval (RAG) and QA (inference) pipelines use the same dependency group. From the **root of the repository**:
 
 ```bash

implementations/xai_refresher/README.md

@@ -93,13 +93,24 @@ are not reliably aligned with prediction sensitivity — especially in early lay
 
 ## Package Dependencies
 
-The Concept Grounding notebook requires Java to be installed. On Linux, you can install it using:
+The Concept Grounding notebook requires Java to be installed.
+
+> **On the Coder platform**, Java is already available. You can verify with:
+>
+> ```bash
+> java -version
+> ```
+
+<details>
+<summary>Not on Coder? Install Java manually</summary>
 
 ```bash
 sudo apt update
 sudo apt install -y default-jre
 ```
 
+</details>
+
 ## Resources
 
 For further reading on the methods covered in this module: