What information does the preface provide about the lineage of Shri Saraswati Gangadhar and the 'Laghu Guru Charitra'?

Chapter 0 explains the lineage of Shri Saraswati Gangadhar, whose surname was Sakhare. His ancestor, Shri Sayandev, received the grace of Shri Narsimha Saraswati Maharaj and was given a boon that his descendants would perform constant service. Shri Saraswati Gangadhar is identified as the fifth descendant from Shri Sayandev. This chapter also introduces a separate work called 'Laghu Guru Charitra,' which consists of only 707 verses and appears to be much older than the more well-known 'Brihad Guru Charitra' by Saraswati Gangadhar.