Add network updates in the releasenote

[vabishaa]

Please provide relevant information, which has to be added to the releasenote for v1.7 Note: @nirupamaBenis please tag other ppl if necessary

[vabishaa]

Network Updates v1.6

• 15 resources joined the network at level 1 via fully dynamic Fair Data Points in the VP Index
• Metadata compliance tests were developed for the use in the onboarding of resources
• Two interactive sessions were conducted with onboarding resources to train them on interacting with the REST API and to run EJP RD metadata compliance tests
• Onboarding office hours became available for Levels 1 and 2, where resources can interact with developers and experts in different tooling for guidance of VP requirement implementation
• Onboarding documentation transferred to the GitHub (The EJP RD Virtual Platform — EJP RD Onboarding Document documentation (vp-onboarding-doc.readthedocs.io))