Add basil to symbol-annotation

[basil]

Description

See jenkinsci/jenkins#5293 (comment) for context. Please let me know if there is anything I can clarify.

Also updating the GitHub URL to reflect the pending split (see HOSTING-1155).

Repositories:

• Current (old): https://github.com/jenkinsci/structs-plugin/tree/master/annotation
• Future (new): https://github.com/basil/lib-symbol-annotation (soon to become https://github.com/jenkinsci/lib-symbol-annotation as of HOSTING-1155).

Submitter checklist for adding or changing permissions

Always

• Add link to plugin/component Git repository in description above

For a newly hosted plugin only

• Add link to resolved HOSTING issue in description above

For a new permissions file only

• Make sure the file is created in permissions/ directory
• artifactId (pom.xml) is used for name (permissions YAML file).
• groupId / artifactId (pom.xml) are correctly represented in path (permissions YAML file)
• Check that the file is named plugin-${artifactId}.yml for plugins

When adding new uploaders (this includes newly created permissions files)

• Make sure to @mention an existing maintainer to confirm the permissions request, if applicable
• Use the Jenkins community (LDAP) account name in the YAML file, not the GitHub account name
• Make sure to @mention the users being added so their GitHub account names are known if they require GitHub merge access (see below).
• All newly added users have logged in to Artifactory at least once

Reviewer checklist (not for requesters!)

• Check this if newly added person also needs to be given merge permission to the GitHub repo (please @ the people/person with their GitHub username in this issue as well). If needed, it can be done using an IRC Bot command
• Check that the $pluginId Developers team has Admin permissions while granting the access.
• In the case of plugin adoption, ensure that the Jenkins Jira default assignee is either removed or changed to the new maintainer.
• If security contacts are changed (this includes add/remove), ping the security officer (currently @daniel-beck) in this pull request. If an email contact is changed, wait for approval from the security officer.

There are IRC Bot commands for it