Add jboss-deployment-structure.xml

[Gallardot]

Add jboss-deployment-structure.xml and Update README

Motivation

Make the installation easier by adding a jboss-deployment-structure.xml file

What

Add the jboss-deployment-structure.xml file

Why

Make the installation easier

How

Verification Steps

Add the steps required to check this change. Following an example.

Touch a dodeploy file into the /opt/jboss/keycloak/standalone/deployments/ subdirectory of your Keycloak installation.

# If your jar file is `keycloak-metrics-spi-2.0.2.jar`
cd /opt/jboss/keycloak/standalone/deployments/
touch keycloak-metrics-spi-2.0.2.jar.dodeploy

Checklist:

• [ ] Code has been tested locally by PR requester
• [ ] Changes have been successfully verified by another team member

Progress

• [x] Finished task
• [ ] TODO

Additional Notes

PS.: Add images and/or .gifs to illustrate what was changed if this pull request modifies the appearance/output of something presented to the users.

[pb82]

this looks good, thanks @Gallardot