Update README.md

README.md

@@ -1 +1,34 @@
 # streamlit-webrtc-example
+
+
+## Manual deployment to heroku
+### Prerequisites
+1. Set up `heroku` command.
+
+2. Add [`heroku-buildpack-apt`](https://github.com/heroku/heroku-buildpack-apt) to buildpacks.
+   ```shell
+   $ heroku buildpacks:add --index 1 heroku-community/apt
+   ```
+
+   See
+   https://help.heroku.com/IYRYW6VB/how-do-i-install-additional-software-packages-that-my-application-requires
+   and
+   https://github.com/heroku/heroku-buildpack-apt
+   for details.
+
+### Deploy
+#### If dependencies have changed, update `requirements.txt`
+1. Generate `requirements.txt`.
+   ```shell
+   $ pipreqs . --force
+   ```
+
+2. Commit it.
+   ```shell
+   $ git add requirements.txt
+   $ git commit -m "requirements.txt"
+   ```
+#### Deploy the current branch to Heroku
+```shell
+$ git push heroku <current-branch>:main
+```