Fixed readme.

README.md

@@ -40,14 +40,13 @@ Before cloning repository, you need these to succesfully use the application.
     ```sh
     cd BP_DP-xlanro00
     ```
-v
+
 4. Create and enter the virtual enviroment.
     ```sh
     virtualenv .venv && source .venv/bin/activate
     ```
 
 5. Install required python modules from requirements.txt.
-
     ```sh
     pip install -r requirements.txt
     ```
@@ -56,6 +55,11 @@ v
 
 # Filtering images
 
+* You will need to enter the virtual enviroment every time you want to use the application. 
+    ```sh
+    source .venv/bin/activate
+    ```
+
 Once all the requirements are installed, the program is ready to use. There are two ways to enter the filters:
 
 1. manually list filter names and parameters from command line