What is the primary purpose and content of the first chapter of the Shri Sai Satcharitra?

The first chapter of the Shri Sai Satcharitra, titled 'Mangalacharan,' primarily consists of traditional invocations to various deities to ensure the successful and obstacle-free completion of the book. As detailed in Chapter 1, the author begins by bowing to Lord Ganesha, the destroyer of obstacles, who is described as Lambodar (large-bellied). The chapter continues with salutations to Goddess Saraswati, the goddess of speech and knowledge, asking for her grace to write the book. It also includes bows to Brahma, Vishnu, and Shankar, and the family deity, Narayana. A central theme throughout, as mentioned in Chapter 1, is the identification of Sai Baba himself with these deities, stating that Sai is Ganesha, who will destroy obstacles, and also Goddess Saraswati, singing his own life story for his devotees' salvation.