feat(only-labels): add 2 new options to distinguish issue and PR configs (#336)

* feat(assignees): add new option to avoid stale for assignees

closes #271

* test: add more coverage

* docs: fix readme format issue

* docs: reorder and enhance typo

* docs(contributing): add more information about the npm scripts

* feat(only-labels): add new options to customize it for issues and PR

closes #308

src/interfaces/issues-processor-options.ts

@@ -19,6 +19,8 @@ export interface IIssuesProcessorOptions {
   closePrLabel: string;
   exemptPrLabels: string;
   onlyLabels: string;
+  onlyIssueLabels: string;
+  onlyPrLabels: string;
   operationsPerRun: number;
   removeStaleWhenUpdated: boolean;
   debugOnly: boolean;