docs: update content descriptions to use consistent language

- Replace "classic literature" with "historical and literary passages/texts"
- Add "randomly excerpted" to accurately describe the content sourcing
- Update both README.md and welcome overlay for consistency
- Remove outdated terminology in favor of more accurate descriptions

README.md

@@ -11,14 +11,14 @@ thumbnail: >-
 
 # Cloze Reader
 
-An interactive cloze reading practice application with AI-powered assistance. Practice reading comprehension by filling in blanks in classic literature passages.
+An interactive cloze reading practice application with AI-powered assistance. Practice reading comprehension by filling in blanks in randomly excerpted historical and literary passages.
 
 ## Features
 
 - **Progressive Level System**: Start with 1 blank, advance to 2-3 blanks as you improve
 - **Smart Hints**: Get word length, first letter, and contextual clues
 - **AI Chat Help**: Click 💬 for intelligent hints about any blank
-- **Classic Literature**: Passages from Project Gutenberg's collection
+- **Historical and Literary Passages**: Randomly excerpted texts from Project Gutenberg's collection
 - **Level-Appropriate Challenges**: Hints adapt based on your current level
 
 ## How to Use

src/welcomeOverlay.js

@@ -43,7 +43,7 @@ class WelcomeOverlay {
       
       <div class="welcome-content">
         <p>
-          <strong>Practice reading comprehension</strong> by filling in missing words from historical and literary texts.
+          <strong>Practice reading comprehension</strong> by filling in missing words from randomly excerpted historical and literary texts.
         </p>
         
         <p>
@@ -51,7 +51,7 @@ class WelcomeOverlay {
         </p>
         
         <p>
-          <strong>Data source:</strong> Historical and literary texts from Project Gutenberg's public domain collection, processed via Hugging Face Datasets.
+          <strong>Data source:</strong> Randomly excerpted historical and literary texts from Project Gutenberg's public domain collection, processed via Hugging Face Datasets.
         </p>
         
         <p style="margin-bottom: 0;">