Added links to Published Works index pages

I have updated the index pages for "Published Works" and "Other Books" to include links to Whitman's short temperance novel Franklin Evans (published on the Whitman Archive under "Periodicals") and to a transcription of Whitman's novel Jack Engle that was recently published in the Walt Whitman Quarterly Review.  Jack Engle is currently being edited for publication on the Whitman Archive. 

~ Nikki