Fix ability to generate new doc

Author: Gaurav0

lib/read-docs.js

@@ -33,9 +33,11 @@ export default function readDocs(
 		)
 
 		if (!runClean) {
-			availableSourceVersions = availableSourceVersions.filter(
-				version => !prevIndexedVersions.includes(version)
-			)
+			if (!ignorePreviouslyIndexedDoc) {
+				availableSourceVersions = availableSourceVersions.filter(
+					version => !prevIndexedVersions.includes(version)
+				)
+			}
 
 			folders = folders.filter(f => {
 				if (!prevIndexedVersions.includes(f) || ignorePreviouslyIndexedDoc) {