Address some checkdoc warnings

[keiravillekode]

for #233

[no important files changed]

[github-actions]

This PR touches files which potentially affect the outcome of the tests of an exercise. This will cause all students' solutions to affected exercises to be re-tested.

If this PR does not affect the result of the test (or, for example, adds an edge case that is not worth rerunning all tests for), please add the following to the merge-commit message which will stops student's tests from re-running. Please copy-paste to avoid typos.

[no important files changed]

For more information, refer to the documentation. If you are unsure whether to add the message or not, please ping @exercism/maintainers-admin in a comment. Thank you!

[keiravillekode]

The following warnings are addressed

 affine-cipher/.meta/example.el:50:2: Warning: docstring wider than 80 characters

 circular-buffer/.meta/example.el:13:5: Warning: ‘(capacity :initarg :capacity :initform 10)’ is a malformed function
 circular-buffer/.meta/example.el:12:11: Warning: reference to free variable ‘circular-buffer’
 circular-buffer/.meta/example.el:22:25: Warning: reference to free variable ‘buf-modulus’
 circular-buffer/.meta/example.el:22:37: Warning: reference to free variable ‘data’
 circular-buffer/.meta/example.el:23:28: Warning: reference to free variable ‘capacity’
 circular-buffer/.meta/example.el:23:11: Warning: assignment to free variable ‘buf-modulus’
 circular-buffer/.meta/example.el:24:11: Warning: assignment to free variable ‘data’
 circular-buffer/.meta/example.el:27:22: Warning: reference to free variable ‘back’
 circular-buffer/.meta/example.el:28:8: Warning: reference to free variable ‘front’
 circular-buffer/.meta/example.el:40:11: Warning: assignment to free variable ‘front’
 circular-buffer/.meta/example.el:44:11: Warning: assignment to free variable ‘back’

 circular-buffer/.meta/example.el:22:16: Warning: the function ‘capacity’ is not known to be defined.
 circular-buffer/.meta/example.el:22:4: Warning: the function ‘with-slots’ is not known to be defined.
 circular-buffer/.meta/example.el:17:5: Warning: the function ‘back’ is not known to be defined.
 circular-buffer/.meta/example.el:16:5: Warning: the function ‘front’ is not known to be defined.
 circular-buffer/.meta/example.el:15:5: Warning: the function ‘data’ is not known to be defined.
 circular-buffer/.meta/example.el:14:5: Warning: the function ‘buf-modulus’ is not known to be defined.
 circular-buffer/.meta/example.el:12:2: Warning: the function ‘defclass’ is not known to be defined.

 circular-buffer/circular-buffer.el:14:11: Warning: reference to free variable ‘circular-buffer’

 circular-buffer/circular-buffer.el:14:2: Warning: the function ‘defclass’ is not known to be defined.

 gigasecond/gigasecond-test.el:13:39: Warning: ‘add’ called with 6 arguments, but accepts only 1
 gigasecond/gigasecond-test.el:17:40: Warning: ‘add’ called with 6 arguments, but accepts only 1
 gigasecond/gigasecond-test.el:21:40: Warning: ‘add’ called with 6 arguments, but accepts only 1
 gigasecond/gigasecond-test.el:25:41: Warning: ‘add’ called with 6 arguments, but accepts only 1
 gigasecond/gigasecond-test.el:29:40: Warning: ‘add’ called with 6 arguments, but accepts only 1

 isogram/.meta/example.el:22:40: Warning: avoid `lsh'; use `ash' instead

 say/.meta/example.el:49:23: Warning: the function ‘number-to-words’ is not known to be defined.
 say/.meta/example.el:25:32: Warning: the function ‘number-to-words-1000’ is not known to be defined.

 secret-handshake/.meta/example.el:18:30: Warning: avoid `lsh'; use `ash' instead

 variable-length-quantity/.meta/example.el:8:2: Warning: docstring wider than 80 characters
 variable-length-quantity/.meta/example.el:12:42: Warning: avoid `lsh'; use `ash' instead

 variable-length-quantity/.meta/example.el:26:21: Warning: avoid `lsh'; use `ash' instead

[fapdash]

One minor change request. It's fine for the first sentence of the edoc to be longer than 80 chars, just not in one line.

[fapdash]

Suggested change

	"Find the modular multiplicative inverse (MMI) of A mod M."
	"Find the modular multiplicative inverse (MMI) of A mod M
	using the extended Euclidean algorithm."