fix: name --offline when given, keep page budget

--offline given with the variable set is named as the option, and the
runs the screen starts get it only when the user gave it. The first
install page stays under its 400 words, the 3.8 runs skip only the
pack test that needs generate_pack.

wiki/first-install.md

@@ -88,12 +88,11 @@ Arrows move, Enter chooses, Esc goes back, as A and B on a handheld.
 
 ## 3. Install
 
-The next screen counts missing files and free space.
+It counts missing files and free space.
 Press Enter on **Install**. **Choose systems** keeps the consoles you
 play.
 
-**Game data** is what a game reads, of no use to other cores. The count
-shows it apart, and its row leaves it out.
+**Game data** (only a game reads it) has its own row.
 
 **Old card?** In a card reader, choose **Copy the BIOS files from your old
 card or a folder**, then the card.
@@ -105,11 +104,11 @@ Esc or Ctrl+C stops, B on a handheld. Run again to resume.
 ## 5. Read the result
 
 - **Done**: all files are in place.
-- **Finished with errors**: run the command again. It retries only those.
+- **Finished with errors**: run it again. It retries only those.
 - **Finished with files missing**: run it again online.
 - **Nothing installed**: the screen says why. See [If it stops](#if-it-stops).
 
-For questions line by line (screen readers), add `--plain`.
+For line-by-line questions (screen readers), add `--plain`.
 
 ## What the command does
 
@@ -132,8 +131,8 @@ All good:
 
 ## Undo
 
-Files it replaces go to a `retrobios-backup` folder beside your BIOS folder.
-The result says how to restore them.
+Replaced files go to `retrobios-backup` beside your BIOS folder. The result
+says how to restore them.
 
 ## If it stops
 
@@ -169,8 +168,7 @@ You cannot write there. Do what the message says.
 
 ### The card is full
 
-Nothing was written. Free some space on the card. On a computer, you can
-also choose another folder.
+Nothing was written. Free some space there.
 
 ### The game still does not start