feat(azkv): Skipping key-version will get latest key

This is a supported behaviour for Azure Key Vault, and is very helpful
when it comes to doing rotation of those keys, as updated versions will
automatically get fetched by sops for new files with no changes to the
config in the repo. This brings AZKV in line with sops' AWS/GCP
integrations, which do not require you to specify a key version.

Thank you to felixfontein for some RST syntax help.

Converted from getsops/sops@eb23541

Co-authored-by: Drum Ogilvie <me@daogilvie.com>
Co-authored-by: Felix Fontein <felix@fontein.de>
Signed-off-by: Drum Ogilvie <me@daogilvie.com>
Signed-off-by: Felix Fontein <felix@fontein.de>

Author: felixfontein

content/en/docs/_index.md

@@ -397,6 +397,13 @@ identifier for a key. This has the following form:
 https://${VAULT_URL}/keys/${KEY_NAME}/${KEY_VERSION}
 ```
 
+You can omit the version, and have just a trailing slash, and this will use
+whatever the latest version of the key is:
+
+```
+https://${VAULT_URL}/keys/${KEY_NAME}/
+```
+
 To create a Key Vault and assign your service principal permissions on
 it from the commandline:
 
@@ -421,6 +428,15 @@ Now you can encrypt a file using:
 ``` sh
 $ sops encrypt --azure-kv https://sops.vault.azure.net/keys/sops-key/some-string test.yaml > test.enc.yaml
 ```
+<<<<<<< HEAD
+=======
+
+or, without the version::
+
+``` sh
+$ sops encrypt --azure-kv https://sops.vault.azure.net/keys/sops-key/ test.yaml > test.enc.yaml
+```
+>>>>>>> 26388ac (feat(azkv): Skipping key-version will get latest key)
 
 And decrypt it using: