Describe the bug

The language in the docs around b-form-radio-group and v-model is very confusing.

Steps to reproduce the bug

1. Go to https://bootstrap-vue.org/docs/components/form-radio/

<b-form-radio> and <b-form-radio-group> do not have a value by default. You must explicitly supply a value (to which the v-model is set to when the radio is checked) via the value prop.

VS next paragraph:

The v-model of both <b-form-radio> and <b-form-radio-group> binds to the checked prop. To pre-check a radio, you must set the v-model value to the radio's value. Do not use the checked prop directly.

These 2 paragraphs are very confusing. First it is stated that you must supply a value to the value prop, then it is stated that in fact, v-model is bound to the checked prop, and finally that you should not use that prop directly anyway.

One might walk away with an understanding of what to do, but not after jumping through a bunch of hoops.

Expected behavior

If the value prop is not bound to v-model, don't say that it must be passed. Why even mention the checked prop if we should not pass it directly anyway? Also I've tested this out, and passing checked seems to work just fine...

Versions

Libraries:

• BootstrapVue: 2.1.0
• Bootstrap: 4.3.1
• Vue: 2.6.10

Environment:

• Device: N/A
• OS: N/A
• Browser: Chrome
• Version: 80

Thanks!