Fixes in 1998/schweikh1/README.md

There was 'I' in the README.md that was an artefact left over from
before the thanks file was introduced so that sentence was removed.

The thanks file was slightly updated too wrt this entry both as a new
category of fixes (the alternate code I made so that it works with macOS
but also referring to the README.md file).

1998/schweikh1/README.md

@@ -52,11 +52,10 @@ respectively, 44 and 46.  But how does this work? Well the string is:
 
 The first number means: the length starting from 0 up through the `>`. The
 second number is the same starting point but up through the `\0` which is why
-it's +2. Somehow it was basic intuition that made me figure out these two
-numbers and a quick test confirmed it. But what happens if only the first number
-is updated? Most of the output will be just `#define` by itself; in the cases
-where there was text after that it was macros that certainly were not defined.
-There might have been other errors as well.
+it's +2. But what happens if only the first number is updated? Most of the
+output will be just `#define` by itself; in the cases where there was text after
+that it was macros that certainly were not defined.  There might have been other
+errors as well.
 
 This allows for opening the right files. The problem with the macOS is
 `/usr/include` does not exist: instead it's