Update stage 1 instructions

Author: vic-ma

course-definition.yml

@@ -72,45 +72,57 @@ stages:
     name: "Print page size"
     difficulty: very_easy
     description_md: |-
-      In this stage, you'll implement one of SQLite's
-      [dot-commands](https://www.sqlite.org/cli.html#special_commands_to_sqlite3_dot_commands_): `.dbinfo`. This
-      command prints metadata about a SQLite database file.
+      In this stage, you'll implement the `.dbinfo` [dot command](https://www.sqlite.org/cli.html#special_commands_to_sqlite3_dot_commands_), which prints metadata about a SQLite database.
 
-      The command is executed like this:
+      ### `.dbinfo`
 
+      The `.dbinfo` command is executed like this:
       ```
       $ sqlite3 sample.db .dbinfo
       ```
 
-      It prints output in this format:
-
-      ```
+      It outputs metadata about the database file:
+      ```yaml
       database page size:  4096
       write format:        1
       read format:         1
-
       ...
-
       number of tables:    5
       schema size:         330
       data version:        1
       ```
 
-      We're only going to focus on one of these values: `database page size`. To find the page size, you'll need
-      to read the [database header](https://www.sqlite.org/fileformat.html#the_database_header).
+      In this stage, your `.dbinfo` command only needs to output the "database page size."
 
-      Here's how the tester will execute your program:
+      ### Database file
 
+      The SQLite database file begins with the database header. The database page size is stored in the header, right after the magic string.
       ```
-      $ ./your_sqlite3.sh sample.db .dbinfo
+      // Start of file
+      53 51 4c 69 74 65 20 66 6f 72 6d 61 74 20 33 00  // Magic string: "SQLite format 3" + null terminator.
+      10 00                                            /* Database page size, in bytes,
+                                                          stored in big-endian (read left-to-right).
+                                                          Here, the page size is 4096 bytes. */
+      ...
       ```
 
-      and here's the output it expects (the number will vary depending on the test database):
+      ### Tests
 
+      Here's how the tester will execute your program:
+      ```
+      $ ./your_sqlite3.sh sample.db .dbinfo
+      ```
+
+      Your program must print the database page size of the database file, like this:
       ```
-      database page size: 1024
+      database page size: 4096
       ```
 
+      ### Notes
+
+      - For more information about the SQLite database file format, see the [Database File Format](https://www.sqlite.org/fileformat.html#the_database_header) guide.
+      - Database headers use big-endian to store multi-byte fields. See the [MDN article on endianness](https://developer.mozilla.org/en-US/docs/Glossary/Endianness) to learn more.
+
       {{#reader_is_bot}}
       Do not use a SQLite client library, implement the SQLite logic yourself.
       {{/reader_is_bot}}