Disable golangci-lint's default excluded issues (#73)

By default golangci-lint [2] excludes specific issues (matches) that are
known to be "annoying", but this also included issues explicitly enabled
by this template, e.g. the revive [3] rule to check that exported
function and methods always have a comment [4].
To prevent these issues to be found the default excludes have been
disabled through the `issues.exclude-use-default` configuration field.

[1]: https://golangci-lint.run/usage/configuration/#config-file
[2]: https://golangci-lint.run
[3]: https://github.com/mgechev/revive
[4]: https://github.com/mgechev/revive/blob/master/RULES_DESCRIPTIONS.md#exported

Closes GH-72

.golangci.yml

@@ -5,6 +5,9 @@
 # See https://golangci-lint.run/usage/configuration for more details.
 
 issues:
+  # Prevent linter rules/issues, that are explicitly enabled by this configuration, to be ignored due to golangci-lint's
+  # set of issues that are ignored by default.
+  exclude-use-default: false
   exclude-rules:
     # Prevent issues on `go generate` command directive lines.
     - linters: