fixing issues #276,#296,#297

Author: gulcingulletutan

_episodes/03-configuration.md

@@ -60,6 +60,8 @@ and then modify it if needed:
   nano ~/.esmvaltool/config-user.yml
 ~~~
 
+Any other editor can be used, e.g.vim.
+
 This file contains the information for:
 
 - Output settings

_episodes/04-recipe.md

@@ -49,7 +49,7 @@ esmvaltool run --config_file ./config-user.yml examples/recipe_python.yml
 If everything is okay, you should see that ESMValTool is printing a lot of
 output to the command line. The final message should be "Run was successful".
 The exact output varies depending on your machine, but it should look something
-like the example output below.
+like the example log output on terminal below.
 
 {% include example_output.txt %}
 

_episodes/07-development-setup.md

@@ -111,6 +111,8 @@ nothing to commit, working tree clean
 
 ### 2 ESMValTool dependencies
 
+Please don’t forget if an esmvaltool environment is already created following the lesson [Installation]({{ page.root }}{% link _episodes/02-installation.md %})., we should choose another name for the new environment in this lesson.
+
 ESMValTool now uses `mamba` instead of `conda` for the recommended installation.
 For a minimal mamba installation, see section **Install Mamba** in lesson
 [Installation]({{ page.root }}{% link _episodes/02-installation.md %}).