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.

1998/tomtorfs/README.md

@@ -99,7 +99,15 @@ Count the number of non-whitespace characters in the source
 file to find out what dark force drove me to write this ;-).
 
 
-### Obfuscation
+### 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 via the source.
+
+If you get stuck, come back and read below for additional hints and information.
+
+
+### How this entry works:
 
 First of all, if you run a C beautifier on the program (thereby of course losing
 the nice code shape I worked so hard on ;-) ) the code will become a bit more

1998/tomtorfs/index.html

@@ -445,7 +445,11 @@ valid exit value to indicate failure (replace them with <code>EOF</code> resp.
 <h3 id="special-notes">Special notes</h3>
 <p>Count the number of non-whitespace characters in the source
 file to find out what dark force drove me to write this ;-).</p>
-<h3 id="obfuscation">Obfuscation</h3>
+<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 via the source.</p>
+<p>If you get stuck, come back and read below for additional hints and information.</p>
+<h3 id="how-this-entry-works">How this entry works:</h3>
 <p>First of all, if you run a C beautifier on the program (thereby of course losing
 the nice code shape I worked so hard on ;-) ) the code will become a bit more
 readable.</p>