Rule: prefer `checkCallback` / `editorCheckCallback` over early return

[joethei]

Bad:

this.addCommand({
			id: 'open-sample-modal-complex',
			name: 'Open sample modal (complex)',
			callback: () => {
				// Conditions to check
				const markdownView = this.app.workspace.getActiveViewOfType(MarkdownView);
				if (!markdownView) {
                    new Notice('Please open a MarkdownView');
                    return;
				}
				new SampleModal(this.app).open();
			}
		});

Good:

this.addCommand({
			id: 'open-sample-modal-complex',
			name: 'Open sample modal (complex)',
			checkCallback: (checking: boolean) => {
				// Conditions to check
				const markdownView = this.app.workspace.getActiveViewOfType(MarkdownView);
				if (markdownView) {
					// If checking is true, we're simply "checking" if the command can be run.
					// If checking is false, then we want to actually perform the operation.
					if (!checking) {
						new SampleModal(this.app).open();
					}

					// This command will only show up in Command Palette when the check function returns true
					return true;
				}
			}
		});