This article first appeared in Radio Times magazine.I first met Jon Snow when I was a young researcher. I was in awe, but as we drove around the UK, making a documentary, we had these wonderful chats. Everybody who’s worked with Jon says this – he was an inspiration.Some 25 years later I found myself in a pub with Jon and his wife, Dr Precious Lunga, discussing a “coming-out” film. Having kept Jon’s Alzheimer’s diagnosis private, they wanted to …