Remove the mention of force-load-at-top from "Invoking Text Directives"

[amccreight]

The section "Invoking Text Directives" includes the sentence "In scroll to the fragment, handle an indicated part that is a range and also prevent fragment scrolling if the force-load-at-top policy is enabled.". However, as of this change that section no longer contains any mention of force-load-at-top, which makes it confusing to read. Probably just the second half of that sentence (starting from "and also") can be removed.