Document Gunicorn worker concurrency

docs/deployment-on-heroku.rst

@@ -16,6 +16,7 @@ Run these commands to deploy the project to Heroku:
     heroku addons:create heroku-redis:hobby-dev
     heroku addons:create mailgun
 
+    heroku config:set WEB_CONCURRENCY=4
     heroku config:set DJANGO_ADMIN_URL="$(openssl rand -base64 32)"
     heroku config:set DJANGO_SECRET_KEY="$(openssl rand -base64 64)"
     heroku config:set DJANGO_SETTINGS_MODULE='config.settings.production'

docs/deployment-on-pythonanywhere.rst

@@ -63,6 +63,7 @@ Add these exports
 
 .. code-block:: bash
 
+    export WEB_CONCURRENCY=4
     export DJANGO_SETTINGS_MODULE='config.settings.production'
     export DJANGO_SECRET_KEY='<secret key goes here>'
     export DJANGO_ALLOWED_HOSTS='<www.your-domain.com>'

{{cookiecutter.project_slug}}/env.example

@@ -4,6 +4,9 @@ POSTGRES_PASSWORD=!!!SET POSTGRES_PASSWORD!!!
 POSTGRES_USER=!!!SET POSTGRES_USER!!!
 CONN_MAX_AGE=
 
+# Gunicorn concurrency
+WEB_CONCURRENCY=4
+
 # Domain name, used by caddy
 DOMAIN_NAME={{ cookiecutter.domain_name }}