docs: Add a "production" overview page.

This pulls together what's covered in detail in several
longer pages, and gives us a page that can serve as a good
drop-in replacement for https://zulip.org/server.html .

Also tweak a couple of related bits for clarity and orthography.

docs/index.rst

@@ -49,6 +49,7 @@ Contents:
    :maxdepth: 2
    :caption: Zulip in production
 
+   Production overview <prod>
    prod-requirements
    Installing a production server <prod-install>
    prod-troubleshooting

docs/prod-requirements.md

@@ -66,15 +66,16 @@ Zulip in production. 64-bit is recommended.
 You should already have a domain name available for your Zulip
 production instance. In order to generate valid SSL certificates with Let's
 Encrypt, and to enable other services such as Google Authentication, you'll
-need to update the domains A record to point to your production server.
+need to update the domain's A record to point to your production server.
 
 ## Credentials needed
 
 #### SSL Certificate
 
-* SSL Certificate for the host you're putting this on (e.g. zulip.example.com).
-  The installation instructions contain documentation for how to get an SSL
-  certificate for free using [LetsEncrypt](https://letsencrypt.org/).
+* An SSL certificate for the host you're putting this on (e.g.,
+  zulip.example.com).  If you don't have an SSL solution already, read
+  about [getting an SSL certificate for free](ssl-certificates.html) using
+  Let's Encrypt.
 
 #### Outgoing email
 

docs/prod.md

@@ -0,0 +1,45 @@
+# Zulip in production
+
+To play around with Zulip and see what it looks like, you can [install
+a dev
+environment](readme-symlink.html#installing-the-zulip-development-environment)
+or check out the [Zulip development community server](chat-zulip-org.html).
+
+If you like what you see, you can set up Zulip for your team by
+installing a production Zulip server.  These pages will walk you
+through how.
+
+## Requirements
+
+You'll [need a few things](prod-requirements.html) to run a production
+Zulip server.  Key requirements include:
+* a dedicated server or VM, running Ubuntu, with at least 2GB of RAM
+  (or 4GB for a large site);
+* a valid DNS name and SSL certificates;
+* a way to send outgoing email.
+
+See [the requirements page](prod-requirements.html) for more details,
+including free options [for SSL](ssl-certificates.html) and [for
+outgoing email](prod-email.html#free-outgoing-smtp) if you don't have
+those already.
+
+## Install
+
+Follow [the install instructions](prod-install.html).  You'll download
+the built release tarball, run the Zulip install script, and configure
+a handful of required settings; then create your Zulip organization
+through your new server's web interface.
+
+## Running
+
+You now have a running Zulip install!
+
+* Read [our advice on helping your community](realm-admin-docs) make
+  the most of Zulip.
+
+* [Customize Zulip](prod-customize.html) to your needs.
+
+* Read about Zulip's support for backups, monitoring, and
+  other [important production considerations](prod-maintain-secure-upgrade.html).
+
+[realm-admin-docs]: https://zulipchat.com/help/getting-your-organization-started-with-zulip

docs/ssl-certificates.md

@@ -42,7 +42,7 @@ renew with this command:
 
 If you aren't able to use Let's Encrypt, you can generate a
 self-signed ssl certificate.  We recommend getting a real certificate
-using LetsEncrypt over this approach because your browser (and some of
+using Let's Encrypt over this approach because your browser (and some of
 the Zulip clients) will complain when connecting to your server that
 the certificate isn't signed.