Updated as per the review comments

Signed-off-by: Abhijit Nathwani <abhijit.nathwani@gmail.com>

Author: abhijitnathwani

README.md

@@ -339,13 +339,13 @@ Customize the output image/video directory location:
 $ git-sim --media-dir=path/to/output status
 ```
 
-Optionally, set the environment variable `git_sim_media_dir` to default that as the media directory, if no `--media-dir` is provided.
+Optionally, set the environment variable `git_sim_media_dir` to set a global default media directory, to be used if no `--media-dir` is provided. Simulated output images/videos will be placed in this location, in subfolders named with the corresponding repo's name.
 
 ```console
 $ export git_sim_media_dir=path/to/media/directory
 $ git-sim status
 ```
-Note: `--media-dir` takes precedence over the environment variable. If you set the environment and still provide the argument, you'll find the media in the path provided by `--media-dir`
+Note: `--media-dir` takes precedence over the environment variable. If you set the environment and still provide the argument, you'll find the media in the path provided by `--media-dir`.
 
 Generate output video in low quality to speed up rendering time (useful for repeated testing, must include `--animate`):
 

git_sim/__main__.py

@@ -85,8 +85,8 @@ def main():
     config.media_dir = os.path.join(os.path.expanduser(args.media_dir), "git-sim_media")
     config.verbosity = "ERROR"
 
-    # If the env variable is set and no argument provideed, use the env variable value
-    if os.getenv('git_sim_media_dir') is not None and args.media_dir == '.':
+    # If the env variable is set and no argument provided, use the env variable value
+    if os.getenv('git_sim_media_dir') and args.media_dir == '.':
         config.media_dir = os.path.join(os.path.expanduser(os.getenv('git_sim_media_dir')), "git-sim_media", repo_name)
 
     if ( args.low_quality ):