Salesforce gives a very cool way to track your Metadata using a report in Summer'18 release. This reports tell what all things you can do with your specific metadata i.e either they are deployable or available in package etc.
Salesforce is also planning to add more channels(like Tooling API, Changeset, Apex Metadata API etc.) in this report which will be really helpful in future.
To access your Metadata Coverage report, go to https://yourOrgUrl/mdcoverage/report.jsp.
There is also a list of metadata which is not included yet. Please go through the link.