I don't know for sure about AMFP becaue I don't think it uses the pre menu more than just setting up the gamma initially.
However, TDD has these entries in the PreMenu category within the english.lang file (I trimmed the contents a bit).
<CATEGORY Name="PreMenu">
<Entry Name="WelcomeMessage01">Welcome to Amnesia: The Dark Descent! [br][br]...</Entry>
<Entry Name="WelcomeMessage02">Amnesia should not be played to win...</Entry>
<Entry Name="WelcomeMessage03">Do not worry about when and how to save during gameplay...</Entry>
<Entry Name="WelcomeMessage04">The world of Amnesia is a dangerous place and you are extremely vulnerable...</Entry>
<Entry Name="WelcomeMessage05">The interplay between light and dark is very important to the game...</Entry>
<Entry Name="WelcomeMessage06">That is all. Hope you enjoy immersing yourself in the world of Amnesia...</Entry>
</CATEGORY>