docs(nav): remove Page component (#7080)
docs(nav): remove Page component (#7080)

`ion-nav` docs refer to the deprecated Page decorator. The example code is already correct.

- Remove Page component reference
driftyco/ionic,dennybiasiolli/ionic,AbraaoAlves/ionic,jarrodkoch/ionic,cambronjay/ionic,cambronjay/ionic,cambronjay/ionic,janglednerves/ionic,driftyco/ionic,AbraaoAlves/ionic,AbraaoAlves/ionic,jarrodkoch/ionic,driftyco/ionic,AbraaoAlves/ionic,janglednerves/ionic,dennybiasiolli/ionic,TillaTheHun0/ionic,jhlee8804/ionic,jhlee8804/ionic,jarrodkoch/ionic,dennybiasiolli/ionic,TillaTheHun0/ionic,joshesp/ionic,alan-agius4/ionic,alan-agius4/ionic,manucorporat/ionic,TillaTheHun0/ionic,alan-agius4/ionic,jhlee8804/ionic,manucorporat/ionic,alan-agius4/ionic,alan-agius4/ionic,alan-agius4/ionic,cambronjay/ionic,joshesp/ionic,janglednerves/ionic,cambronjay/ionic,driftyco/ionic,jhlee8804/ionic,manucorporat/ionic,jarrodkoch/ionic,jarrodkoch/ionic,janglednerves/ionic,brianespinosa/ionic2-sass,joshesp/ionic,jhlee8804/ionic,dennybiasiolli/ionic,driftyco/ionic,manucorporat/ionic,joshesp/ionic,janglednerves/ionic,AbraaoAlves/ionic,TillaTheHun0/ionic,manucorporat/ionic,dennybiasiolli/ionic