Updated contributing.md to update steps to run locally

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

Author: abhijitnathwani

CONTRIBUTING.md

@@ -41,38 +41,24 @@ steps:
 so that you have a copy on GitHub that you can clone and work with
 3) Clone the codebase down to your local machine
 4) For the code to run locally without getting a `ModuleNotFoundError`,
-you need to remove the import prefix `git_sim.` from imports (for example
-`from git_sim_base_command import GitSimBaseCommand`) in the following files:
-
-- __main.py__
-- git_sim.py
-- git_sim_add.py
-- git_sim_branch.py
-- git_sim_cherrypick.py
-- git_sim_commit.py
-- git_sim_log.py
-- git_sim_merge.py
-- git_sim_rebase.py
-- git_sim_reset.py
-- git_sim_restore.py
-- git_sim_revert.py
-- git_sim_stash.py
-- git_sim_status.py
-- git_sim_tag.py
-
-There is probably a way around this. When I figure it out I'll update this guide.
-
-5) You can run your local Git-Sim commands from within other local repos like this:
-
+install the developement package by running
+```console
+$ cd git-sim
+$ python setup.py develop
 ```
-$ python ~/path/to/git-sim/git_sim/__main__.py [global options] <subcommand> [subcommand options]
+This will install sources from your cloned repo such that you can edit the source and the changes are reflected instantly.
+
+1) You can run your local Git-Sim commands from within other local repos like this:
+
+```console
+$ git-sim [global options] <subcommand> [subcommand options]
 ```
 
 For example, you can simulate the `git add` command locally like this:
 
-```
+```console
 $ cd path/to/any/local/git/repo
-$ python ~/path/to/git-sim/git_sim/__main__.py --animate add newfile.txt
+$ git-sim --animate add newfile.txt
 ```
 
 6) After pushing your code changes up to your fork, [submit a pull request](https://github.com/initialcommit-com/git-sim/compare) for me