Mozilla should provide a template like these for manual setup

pontoon.env

ADMIN_EMAIL=pontoon@example.com
# Optional. Email address for the ADMINS setting.
ADMIN_NAME=pontoon-admin
# Optional. Name for the ADMINS setting.
AUTHENTICATION_METHOD=django
# The default value is django, which allows you to log in via accounts created using manage.py shell. Set to ‘fxa’ if you want to use ‘Firefox Accounts’ (corresponding FXA_* settings must be set). Set to ‘github’ if you want to use ‘GitHub’ (corresponding GITHUB_* settings must be set). Set to ‘gitlab’ if you want to use ‘GitLab’ (corresponding GITLAB_* settings must be set if required). Set to ‘google’ if you want to use ‘Google’ (corresponding GOOGLE_* settings must be set).
CELERY_ALWAYS_EAGER=false
# Controls whether asynchronous tasks (mainly used during sync) are sent to Celery or executed immediately and synchronously. Set this to False on production.
CELERYD_MAX_TASKS_PER_CHILD=20
# Maximum number of tasks a Celery worker process can execute before it’s replaced with a new one. Defaults to 20 tasks.
DISABLE_COLLECTSTATIC=1
# Disables running ./manage.py collectstatic during the build. Should be set to 1.

# Heroku’s Python buildpack has a bug that causes issues when running 
# node binaries during the compile step of the buildpack. 
# To get around this, we run the command in our post-compile step (see bin/post_compile)
# when the issue doesn’t occur.

DJANGO_DEBUG=false
# Controls DEBUG mode for the site. Should be set to False in production.
DJANGO_DEV=false
# Signifies whether this is a development server or not. Should be False in production. Adds some additional django apps that can be helpful during day to day development.
ENABLE_BUGS_TAB=
# Optional. Enables Bugs tab on team pages, which pulls team data from bugzilla.mozilla.org. Specific for Mozilla deployments.
ERROR_PAGE_URL=
# Optional. URL to the page displayed to your users when the application encounters a system error. See Heroku Reference for more information.
GOOGLE_ANALYTICS_KEY=
# Optional. Set your Google Analytics key to use Google Analytics.
GOOGLE_TRANSLATE_API_KEY=
# Optional. Set your Google Cloud Translation API key to use machine translation by Google.
LOCALE_REQUEST_FROM_EMAIL=pontoon@example.com
# Optional. Requests for new project locales are sent from this email.
MAINTENANCE_PAGE_URL=
# Optional. URL to the page displayed to your users when the application is placed in the maintenance state. See Heroku Reference for more information.
MANUAL_SYNC=true
# Optional. Enable Sync button in project Admin.
MICROSOFT_TRANSLATOR_API_KEY=
# Optional. Set your Microsoft Translator API key to use machine translation by Microsoft.
NEW_RELIC_API_KEY=
# Optional. API key for accessing the New Relic REST API. Used to mark deploys on New Relic.
NEW_RELIC_APP_NAME=
# Optional. Name to give to this app on New Relic. Required if you’re using New Relic.
PROJECT_MANAGERS=
# Optional. A list of project manager email addresses to send project requests to
SECRET_KEY=
# Required. Secret key used for sessions, cryptographic signing, etc.
SITE_URL=
# Controls the base URL for the site, including the protocol and port. Defaults to http://localhost:8000, should always be set in production.
SSH_CONFIG=
# Contents of the ~/.ssh/config file used when Pontoon connects to VCS servers via SSH. Used for disabling strict key checking and setting the default user for SSH. For example:

# StrictHostKeyChecking=no
# 
# Host hg.mozilla.org
# User pontoon@mozilla.com
# 
# Host svn.mozilla.org
# User pontoon@mozilla.com

SSH_KEY=
# SSH private key to use for authentication when Pontoon connects to VCS servers via SSH.

# Note
# 
# Changing the SSH_CONFIG or SSH_KEY environment variables requires a rebuild of the site, as these settings are only used at build time. Simply changing them will not actually update the site until the next build.
# 
# The Heroku Repo plugin includes a rebuild command that is handy for triggering builds without making code changes.

# Note
# 
# Some environment variables, such as the SSH-related ones, may contain newlines. The easiest way to set these is using the heroku command-line tool to pass the contents of an existing file to them:

# heroku config:set SSH_KEY="`cat /path/to/key_rsa`"

STATIC_HOST=
# Optional. Hostname to prepend to static resources paths. Useful for serving static files from a CDN. Example: //asdf.cloudfront.net.
SVN_LD_LIBRARY_PATH=
# Path to prepend to LD_LIBRARY_PATH when running SVN. This is necessary on Heroku because the Python buildpack alters the path in a way that breaks the built-in SVN command. Set this to /usr/lib/x86_64-linux-gnu/.
SYNC_TASK_TIMEOUT=3600
# Optional. Multiple sync tasks for the same project cannot run concurrently to prevent 
# potential DB and VCS inconsistencies. We store the information about the running task 
# in cache and clear it after the task completes. 
# In case of an error, we might never clear the cache, 
# so we use SYNC_TASK_TIMEOUT as the longest possible period after which the cache is 
# cleared and the subsequent task can run. The value should exceed the longest sync task of the instance. 
# The default value is 3600 seconds (1 hour).

SYSTRAN_TRANSLATE_API_KEY=
# Optional. Set your `SYSTRAN Translate API key`_ to use machine translation by SYSTRAN.
TZ=UTC
# Timezone for the dynos that will run the app. Pontoon operates in UTC, so set this to UTC.
VCS_SYNC_NAME=Pontoon
# Optional. Default committer’s name used when committing translations to version control system.
VCS_SYNC_EMAIL=pontoon@example.com
# Optional. Default committer’s email used when committing translations to version control system.