Meta: Fix broken external links

Meta/Lagom/ReadMe.md never had any other name; not sure how that typo
happened.

The link to the non-existent directory is especially vexing because the
text goes on to explain that we don't want such a directory to exist.

Found by running markdown-checker, and 'wget'ing all external links.

Meta/Lagom/Fuzzers/FuzzilliJsInstructions.md

@@ -2,7 +2,7 @@
 
 1. Download a copy of the Fuzzilli repo from https://github.com/googleprojectzero/fuzzilli
 2. Install Swift and make sure it's in your path environment variable.
-3. Build FuzzilliJs as you would the other fuzzers. [See README.md in the parent folder.](https://github.com/SerenityOS/serenity/blob/master/Meta/Lagom/README.md)
+3. Build FuzzilliJs as you would the other fuzzers. [See ReadMe.md in the parent folder.](https://github.com/SerenityOS/serenity/blob/master/Meta/Lagom/ReadMe.md)
 4. Apply the add-serenity-support-to-fuzzilli.patch patch file to the Fuzzilli root directory. ```patch -p1 < /path/to/add-serenity-support-to-fuzzilli.patch```
 5. Build Fuzzilli with ```swift build -c release```
 6. Run Fuzzilli with ```swift run -c release FuzzilliCli --profile=serenity /path/to/FuzzilliJs```. See ```swift run FuzzilliCli --help``` for options.

Meta/Lagom/ReadMe.md

@@ -49,7 +49,7 @@ We have a [bmp suite and a jpg suite and several others](https://github.com/Sere
 They are GPL'ed, and therefore not quite as compatible with the rest of Serenity.
 That's probably not a problem, but keeping "our" testcases separate from those GPL'ed suits sounds like a good idea.
 
-We could keep those testcases somewhere else in the repository, like [a `fuzz` directory](https://github.com/SerenityOS/serenity/tree/master/Base/res/html/misc/jpgsuite_files/fuzz).
+We could keep those testcases somewhere else in the repository, like a `fuzz` directory.
 But fuzzing tends to generate more and more and more files, and they will blow up in size.
 Especially if we keep all interesting testcases, which is exactly what I intend to do.