feat: Update Docker configuration and README.md

The Docker configuration has been updated to include the necessary steps for running the project. Additionally, the README.md file has been modified to provide clearer instructions for running the project using Docker.

README.md

@@ -2,9 +2,17 @@
 
 Backend for ngo dedicated to the rescue of abandoned animals in the streets. This backend is being developed in NodeJs as a collaboration with El Rincón Institute mentoring the student Kilian Sosa.
 
-To run the project: 
-1. Install the proper NodeJs version recommended in the package.json file
-2. Run: ```npm run start```
+To run the project:
+
+1. Install docker and run it
+2. docker build -t gatos-sin-hogar-backend .
+3. docker run -p 8080:7000 gatos-sin-hogar-backend
 
 IMPORTANT
 This project has a frontend repository related
+
+To have in mind:
+
+User from EC2 needs permissions to interact with Docker
+(Run this command in EC2 for troubleshooting)
+sudo usermod -aG docker $USER