How does the concept of Nishkam Guru service, as detailed in Chapter 0, specifically apply to the act of writing a Guru's biography?

Chapter 0 explains that Nishkam Guru service is performed for liberation from the cycle of birth and death, and it is considered superior to service performed with desire (Kamya). When applied to writing a Guru's biography, this act becomes a form of Nishkam service. The text further elaborates that by studying and performing Parayans of such a detailed poetic Guru biography, the writer not only performs this selfless service but also enables other devotees to do the same. This allows the writer to gain the merit of serving God in humanity (Jan-Janardan) while helping others achieve the purpose of their lives.