Missing rules (ongoing)

[ilya-lesikov]

• force one-line if err:= func(); err != nil, if one err argument returned`. To ignore this behavior rename err to anything else
• expand fields to key: value in structs when no key specified
• function/method definition arguments are always on a single line

Implement in linter:

• fields in inline anonymous structs, when structs defined outside of the file, and keys of the fields are not specified, should not be sorted but should fail with a message like "un-keyed field definitions disallowed"