ELS-987: add instructions for setting up an OL 7 mirror

Author: deynekoaa

docs/local-mirror-els/README.md

@@ -123,4 +123,18 @@ rsync://repo.tuxcare.com/CENTOS8STREAMELS/
 For example:
 ```
 rsync -avSHP --delete rsync://repo.tuxcare.com/CENTOS8STREAMELS/ .
+```
+
+### OracleLinux 7 ELS
+
+To create a local mirror of the repository with security updates via `rsync`, use the following:
+
+```
+rsync://repo.tuxcare.com/ORACLELINUX7ELS/
+```
+
+For example:
+
+```
+rsync -avSHP --delete rsync://repo.tuxcare.com/ORACLELINUX7ELS/ .
 ```