add notices to those who wish for a greater challenge

We add the following level-3 header to help people identify text
they may wish to skip if they wish for a greater challenge:

```
```

After that notice we add:

```
**If you want a greater challenge, don't read any further**:
just try to understand the program via the source.

If you get stuck, come back and read below for additional hints and information.
```

And sometimes follow with:

```
```

Or sometimes follow with:

```
```

Where the alt code impacts a "greater challenge", we add instead:

```
**If you want a greater challenge, don't read any further**:
just try to understand the program without looking at the Alternate code.

If you get stuck, come back and look at the Alternate code.
```

And where a given command impacts a "greater challenge", we add instead:

```
**If you want a greater challenge, don't read any further**:
just try to understand the program without running the command below.

If you get stuck, come back and run the following command:
```

Perform `make www` to perform the above and test under macOS.

2018/yang/Makefile

@@ -169,17 +169,16 @@ generated5.c: ${PROG}.c right shift
 	@${RM} -f $@
 	./shift < $< | ./right > $@
 
-############
-# spoilers #
-############
+########################
+# detailed information #
+########################
 
-spoiler: spoilers
+details:
+	@echo "Really show the detailed information?  If you must see it run:"
+	@echo
+	@echo "   make i_give_up_show_me_the_details"
 
-spoilers:
-	@echo "Really show spoilers?  Please build this target to confirm:"
-	@echo "   i_give_up_show_me_the_spoilers"
-
-i_give_up_show_me_the_spoilers: msg3 msg4 msg5 msg6 msg7 msg8 msg9
+i_give_up_show_me_the_details: msg3 msg4 msg5 msg6 msg7 msg8 msg9
 
 msg3: generated6.c
 	$(CC) $(CFLAGS) $< -o $@
@@ -229,13 +228,11 @@ generated11.c: generated10.c right shift
 generated12.c: msg7
 	./msg7 > $@
 
-####################################
-# spoilers for the truly impatient #
-####################################
+#####################################################
+# final information message for the truly impatient #
+#####################################################
 
-spoiler_for_the_truly_impatient: i_just_want_to_see_the_final_message
-
-i_just_want_to_see_the_final_message: msg11.txt
+the_last_word: msg11.txt
 	@${CAT} $<
 
 msg11.txt: msg11 ${PROG}.c

2018/yang/README.md

@@ -42,15 +42,6 @@ reveal messages and one more tool that can be used to reveal the final message
 hidden in the original source.  All of these can be created using combinations
 of `./left`, `./right` and `./shift` and the additionally generated programs.
 
-The final message can be revealed using
-
-``` <!---sh-->
-    ./msg9 < prog.c
-```
-
-But what combinations will generate `./msg3`, `./msg4`, `./msg5`, `./msg6`,
-`./msg7`, `./msg8` and finally `./msg9`?
-
 
 ## Author's remarks:
 
@@ -169,6 +160,34 @@ will look weird after rotation, for example.
 `Nuko` compiles without warnings with all compilers above, even with
 `-Wall -Wextra -pedantic` for gcc and clang.
 
+
+### NOTICE to those who wish for a greater challenge
+
+**If you want a greater challenge, don't read any further**:
+just try to understand the program without running the command below.
+
+If you get stuck, come back and run the following command:
+
+``` <!---sh-->
+    ./msg9 < prog.c
+```
+
+But what combinations will generate `./msg3`, `./msg4`, `./msg5`, `./msg6`,
+`./msg7`, `./msg8` and finally `./msg9`?
+
+For more hints try:
+
+``` <!---sh-->
+    make details
+```
+
+And for the last word, try:
+
+``` <!---sh-->
+    make the_last_word
+```
+
+
 <!--
 
     Copyright © 1984-2024 by Landon Curt Noll. All Rights Reserved.

2018/yang/index.html

@@ -424,10 +424,6 @@ that this remark is completely misleading.</p>
 reveal messages and one more tool that can be used to reveal the final message
 hidden in the original source. All of these can be created using combinations
 of <code>./left</code>, <code>./right</code> and <code>./shift</code> and the additionally generated programs.</p>
-<p>The final message can be revealed using</p>
-<pre><code>    ./msg9 &lt; prog.c</code></pre>
-<p>But what combinations will generate <code>./msg3</code>, <code>./msg4</code>, <code>./msg5</code>, <code>./msg6</code>,
-<code>./msg7</code>, <code>./msg8</code> and finally <code>./msg9</code>?</p>
 <h2 id="authors-remarks">Author’s remarks:</h2>
 <h3 id="tools-usage">Tools’ usage:</h3>
 <p><code>Nuko</code> is a text rotator: given some text in <code>stdin</code>, <code>Nuko</code> will write the
@@ -509,6 +505,17 @@ will look weird after rotation, for example.</p>
 </ul>
 <p><code>Nuko</code> compiles without warnings with all compilers above, even with
 <code>-Wall -Wextra -pedantic</code> for gcc and clang.</p>
+<h3 id="notice-to-those-who-wish-for-a-greater-challenge">NOTICE to those who wish for a greater challenge</h3>
+<p><strong>If you want a greater challenge, don’t read any further</strong>:
+just try to understand the program without running the command below.</p>
+<p>If you get stuck, come back and run the following command:</p>
+<pre><code>    ./msg9 &lt; prog.c</code></pre>
+<p>But what combinations will generate <code>./msg3</code>, <code>./msg4</code>, <code>./msg5</code>, <code>./msg6</code>,
+<code>./msg7</code>, <code>./msg8</code> and finally <code>./msg9</code>?</p>
+<p>For more hints try:</p>
+<pre><code>    make details</code></pre>
+<p>And for the last word, try:</p>
+<pre><code>    make the_last_word</code></pre>
 <!--
 
     Copyright © 1984-2024 by Landon Curt Noll. All Rights Reserved.