Add custom-id

Author: Siva Manivannan

docs/reference/replicated-cli-customer-create.md

@@ -38,14 +38,22 @@ replicated customer create [Flags]
     <td>duration</td>
     <td>If set, license will expire a specified number of units from the current time. For example, <code>2h</code> or <code>1h60m</code> or <code>120m</code> are all the same duration.</td>
   </tr>
+  <tr>
+    <td><code>--custom-id</code></td>
+    <td>string</td>
+    <td>If set, this custom alphanumeric ID is associated with this customer to more easily tie this record to your external data systems (i.e. Salesforce, Hubspot, etc.) </td>
+  </tr>
   <Help/>
   <App/>
   <Token/>
 </table>
 
 ## Examples
 ```bash
-replicated customer create --channel Megacorp_Beta --name "Megacorp" --ensure-channel --expires-in "8760h"
-ID                                  NAME        CHANNELS         EXPIRES                          TYPE
-2u4KGXSY65SAUW0ltG_pPhxBGPJ4XNSS    Megacorp    Megacorp_Beta    2021-01-20 00:17:38 +0000 UTC    dev
+replicated customer create --channel Megacorp_Beta --name "Megacorp" --ensure-channel --expires-in "8760h" --custom-id "salesforceid-123"
+```
+
+```bash
+ID                                  NAME        CHANNELS         EXPIRES                          TYPE    CUSTOM_ID
+2u4KGXSY65SAUW0ltG_pPhxBGPJ4XNSS    Megacorp    Megacorp_Beta    2021-01-20 00:17:38 +0000 UTC    dev     salesforceid-123
 ```

docs/reference/replicated-cli-customer-ls.md

@@ -29,9 +29,9 @@ List all customers:
 
 ```bash
 replicated customer ls
-ID                                  NAME                            CHANNELS         EXPIRES    TYPE
-iEgJuVDHy2pi-AqOjLXbZCTX9bqlV6YH    John Smith                      Unstable         Never      
-YAg7ripYbK0tM5MVn_81nMy0YrhBsHrm    Megacorp                        Megacorp_Beta    Never      
+ID                                  NAME                            CHANNELS         EXPIRES    TYPE    CUSTOM_ID
+iEgJuVDHy2pi-AqOjLXbZCTX9bqlV6YH    John Smith                      Unstable         Never              Not Set
+YAg7ripYbK0tM5MVn_81nMy0YrhBsHrm    Megacorp                        Megacorp_Beta    Never              salesforceid-123
 ```
 
 List customers and their instances for a specific application version: