feat: initiate swagger

feat: added userService url in config

feat: modified create book resolver

feat: created service to validate user

Merge branch 'master' of https://github.com/TheJSGirl/graphql-book-store

feat: created resolver to remove the author

Merge pull request #3 from TheJSGirl/bugfix/update-resolvers

feat: added mutation to remove author

fix: updating null values correction

Merge pull request #2 from TheJSGirl/feat/crud-resolvers

Merge branch 'master' of https://github.com/TheJSGirl/graphql-book-store into feat/crud-resolvers

fix: update only authors

Merge pull request #1 from TheJSGirl/refactor

refactor: divided mutations and root queries in separate files

feat: update authors