fix: type errors on description block and match method name to docs

Author: srtaalej

packages/web-api/src/types/request/slacklists.ts

@@ -1,4 +1,4 @@
-import type { Block, KnownBlock } from '@slack/types';
+import type { RichTextBlock } from '@slack/types';
 
 import type { TokenOverridable } from './common';
 

packages/web-api/test/types/methods/slacklists.test-d.ts

@@ -6,11 +6,11 @@ const web = new WebClient('TOKEN');
 
 // slackLists.create
 // -- sad path
-expectError(web.slacklists.create()); // lacking argument
-expectError(web.slacklists.create({})); // missing name
+expectError(web.slackLists.create()); // lacking argument
+expectError(web.slackLists.create({})); // missing name
 
 // -- happy path
-expectAssignable<Parameters<typeof web.slacklists.create>>([
+expectAssignable<Parameters<typeof web.slackLists.create>>([
   {
     name: 'Backlog',
   },