Document the docker images which are automatically built.

This closes #115, after being implemented in #117.

README.md

@@ -20,6 +20,7 @@ Table of Contents
 
 
 
+
 # RSS2Email
 
 This project began life as a naive port of the python-based [r2e](https://github.com/wking/rss2email) utility to golang.
@@ -35,6 +36,7 @@ Over time we've now gained a few more features:
 
 
 
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 # Installation
 
 If you have golang installed you can fetch, build, and install the latest binary by running:
@@ -54,6 +56,12 @@ go build .
 go install .
 ```
 
+Finally you can find automatically generated docker images, these are built on a nightly basis, and when releases are made:
+
+* https://github.com/skx/rss2email/pkgs/container/rss2email
+
+
+
 **Version NOTES**:
 
 * You'll need go version **1.17** or higher to build.
@@ -72,6 +80,8 @@ source <(rss2email bash-completion)
 ```
 
 
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+
 # Feed Configuration
 
 Once you have installed the application you'll need to configure the feeds to monitor, this could be done by editing the configuration file:
@@ -112,6 +122,7 @@ Adding per-feed items allows excluding feed-entries by regular expression, for e
 
 
 
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 # Usage
 
 Once you've populated your feed list, via a series of `rss2email add ..` commands, or by editing the configuration file directly, you are now ready to actually launch the application.
@@ -140,6 +151,7 @@ The state of feed-entries is recorded beneath `~/.rss2email/state.db`, which is
 
 
 
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 # Daemon Mode
 
 Typically you'd invoke `rss2email` with the `cron` sub-command as we documented above.  This works in the naive way you'd expect:
@@ -164,6 +176,7 @@ In short the process runs forever, in the foreground.  This is expected to be dr
 
 
 
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 # Initial Run
 
 When you add a new feed all the items contained within that feed will initially be unseen/new, and this means you'll receive a flood of emails if you were to run:
@@ -178,6 +191,8 @@ record each item as having been seen, rather than sending you emails:
      $ rss2email cron -send=false user@domain.com
 
 
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+
 # Assumptions
 
 Because this application is so minimal there are a number of assumptions baked in:
@@ -190,6 +205,7 @@ Because this application is so minimal there are a number of assumptions baked i
 
 
 
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 # SMTP Setup
 
 By default the outgoing emails we generate are piped to `/usr/sbin/sendmail` to be delivered.  If that is unavailable, or unsuitable, you can instead configure things such that SMTP is used directly.
@@ -208,6 +224,7 @@ If those values are present then SMTP will be used, otherwise the email will be
 
 
 
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 # Email Customization
 
 By default the emails are sent using a template file which is embedded in the application.  You can override the template by creating the file `~/.rss2email/email.tmpl`, if that is present then it will be used instead of the default.
@@ -230,6 +247,7 @@ If you're a developer who wishes to submit changes to the embedded version you s
 **NOTE**: If you read the earlier section on configuration you'll see that it is possible to add per-feed configuration values to the config file.  One of the supported options is to setup a feed-specific template-file.
 
 
+
 ## Changing default From address
 
 As noted earlier when sending the notification emails the recipient address is used as the sender-address too.   There are no flags for changing the From: address used to send the emails, however using the section above you can [use a customized email-template](#email-customization), and simply update the template to read something like this:
@@ -246,6 +264,7 @@ X-RSS-Feed: {{.Feed}}
 
 
 
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 # Implementation Overview
 
 The two main commands are `cron` and `daemon` and they work in roughly the same way:
@@ -261,6 +280,8 @@ The two main commands are `cron` and `daemon` and they work in roughly the same
 The other subcommands mostly just interact with the feed-list, via the use of [configfile/configfile.go](configfile/configfile.go) to add/delete/list the contents of the feed-list.
 
 
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+
 # Github Setup
 
 This repository is configured to run tests upon every commit, and when