adding a script on how to calculated the encoded password format with…

[elangelo]

… bash

https://issues.apache.org/jira/browse/SOLR-XXXXX

Description

Adding a short bash script in the documentation that illustrates how to calculate the encoded password format for security.json

Solution

doc

Tests

doc only

Checklist

Please review the following and check all that apply:

• [v ] I have reviewed the guidelines for How to Contribute and my code conforms to the standards described there to the best of my ability.
• I have created a Jira issue and added the issue ID to my pull request title.
• I have given Solr maintainers access to contribute to my PR branch. (optional but recommended, not available for branches on forks living under an organisation)
• [ v] I have developed this patch against the main branch.
• I have run ./gradlew check.
• I have added tests for my changes.
• [ v] I have added documentation for the Reference Guide