add usage guide with practical examples

[rootdevss]

hey, made a usage guide to help people who want to use the repo data but dont know where to start

the repo updates multiple times per week but lacks documentation on how to actually use the data in practice, so i created this guide with:

• python code examples for parsing api dump and fvariables
• real world use cases like detecting breaking changes and new apis
• automation scripts with github actions and discord/telegram webhooks
• explanation of how to interpret each file in the repo
• best practices tips and version comparison methods

thought it would add a lot of value for the community who wants to extract insights from the automated data

[rootdevss]

hey @MaximumADHD, this pr adds a practical usage guide for the repo data

saw that pr #27 added similar documentation to the readme and thought this would complement it nicely. the guide includes:

• code examples for parsing the dumps
• automation scripts for monitoring updates
• real use cases the community might find helpful

lmk if you'd like any changes or if this fits the repo's direction