Struct tag boolean values are not parsed properly when specified with double quotes

[fchikwekwe]

The README shows this example in the Sample struct:

...
Working bool   `default:"true"`
...

When running the tests in the defaults_test.go boolean values are not properly being parsed when specified in double quotes above. The following pattern passes:

...
Working bool   `default:true`
...

However this is not a preferred way to specify tags in yaml. I'm validating whether this is based on a recent change to the defaults library behavior or if it is related to a specific go version. If I can validate the isssue, I may open a PR related to this soon.

[robbkidd]

I've reproduced in a draft PR the ultimate issue: a person cannot set a false value on a boolean field that has a default of true. @fchikwekwe and I were able to sort of work around this by flubbing the default: tag annotation syntax.

[robbkidd]

Updated the PR to demonstrate that a bool pointer is necessary to be able to have a boolean field that defaults to true and still be able for a user to set the field to false. If this is the only or best way to accomplish default-true booleans, we can open a new PR or update the existing one to not add tests but instead update the README documentation to warn users about defaulting a bool field to true and recommend using a *bool.

[fchikwekwe]

The scope of this issue is now to document the boolean pointer workaround in the README. I'll open a PR for that and link it shortly.

[robbkidd]

Then I discover #15 and #30 which describe the same situation. In addition to documenting "bool fields set to default:'true' will not behave how you might think!" would it be helpful for the library to warn or error when setting a field of type bool whose default is true?