get-zones should comment out NAMESERVER() (#743)

* get-zones should comment out NAMESERVER()

* Edits

docs/get-zones.md

@@ -9,12 +9,51 @@ DNSControl has a stand-alone utility that will contact a provider,
 download the records of one or more zones, and output them to a file
 in a variety of formats.
 
-The original purpose of this command is to help convert legacy domains
-to DNScontrol (bootstrapping).  Since bootstrapping can not depend on
-`dnsconfig.js`, `get-zones` relies on command line parameters and
-`creds.json` exclusively.
+`get-zones` relies on command line parameters and `creds.json`
+exclusively.  It does not use `dnsconfig.js`. This is to assist
+bootstrapping a new system.
 
-Syntax:
+## Use case 1: Bootstrapping a new system
+
+If you are moving a DNS zone from a provider to DNSControl, this
+command will do most of the work for you by downloading the records
+and writing them out in `dnsconfig.js`-format. It is intended to be
+"a decent first draft", only requiring minimal editing.
+
+Use `--format=djs` or `--format=js` (djs is recommended).
+
+Minor editing is required. Not all record formats are supported.
+SOA records are commented out, since most providers do not support it.
+BIND supports it, but requires the data to be entered as meta data.
+
+The `NAMESERVER()` command is generated commented out. This is usually
+not needed as DNSControl can get more accurate information via the
+API. Remove the comments only to override the DNS service provider.
+
+## Use case 2: Generating BIND ZONE files
+
+The `--format=zone` generates BIND-style Zonefiles. Pseudo records not
+supported by BIND are generated as comments.
+
+This format is useful when moving zonedata between providers, since
+the format is relatively universal.
+
+This format is also useful for generating backups of DNS zones. Unlike
+making a backup of the `dnsconfig.js`, this is the raw records, which
+may be useful.
+
+## Use case 3: TAB separated values
+
+The goal of `--format=tsv` is to provide a high-fidelity format that is easy
+enough to parse with `awk`.
+
+## Use case 4: List zones
+
+If a provider supports it, `--format=nameonly` lists the names of the
+zones at the provider.
+
+
+## Syntax
 
    dnscontrol get-zones [command options] credkey provider zone [...]
 
@@ -44,7 +83,8 @@ The columns in --format=tsv are:
 
 The --ttl flag only applies to zone/js/djs formats.
 
-EXAMPLES:
+## Examples
+
    dnscontrol get-zones myr53 ROUTE53 example.com
    dnscontrol get-zones gmain GANDI_V5 example.comn other.com
    dnscontrol get-zones cfmain CLOUDFLAREAPI all
@@ -54,11 +94,10 @@ EXAMPLES:
 Read a zonefile, generate a JS file, then use the JS file to see how
 different it is from the zonefile:
 
-   dnscontrol get-zone --format=js -out=foo.djs bind BIND example.org 
+   dnscontrol get-zone --format=djs -out=foo.djs bind BIND example.org 
    dnscontrol preview --config foo.js
 
-
-# Developer Note
+# Developer Notes
 
 This command is not implemented for all providers.
 
@@ -88,12 +127,12 @@ and return them as a list of RecordConfig structs.
 
 The code to do that already exists in `GetDomainCorrections`.
 You should extract it into its own function (`GetZoneRecords`), rather
-than having it be burried in the middle of `GetDomainCorrections`.
+than having it be buried in the middle of `GetDomainCorrections`.
 `GetDomainCorrections` should call `GetZoneRecords`.
 
 Once that is done the `get-zone` subcommand should work.
 
-**Step 4. Optionally implemement the `ListZones` function**
+**Step 4. Optionally implement the `ListZones` function**
 
 If the `ListZones` function is implemented, the "all" special case
 will be activated.  In this case, listing a single zone named `all`