docs(forms): change inline custom radio name

[julien-deramond]

Using the name "customRadioInline1" is confusing because it is also used by id/for for the first custom radio.

As we can see in the previous example of the documentation (https://getbootstrap.com/docs/4.5/components/forms/#radios), we have customRadio and not customRadio1.

Note: the documentation in v5 is correct, it uses "inlineRadioOptions":

<div class="form-check form-check-inline">
  <input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio1" value="option1">
  <label class="form-check-label" for="inlineRadio1">1</label>
</div>
<div class="form-check form-check-inline">
  <input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio2" value="option2">
  <label class="form-check-label" for="inlineRadio2">2</label>
</div>
<div class="form-check form-check-inline">
  <input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio3" value="option3" disabled>
  <label class="form-check-label" for="inlineRadio3">3 (disabled)</label>
</div>

[patrickhlauke]

Yup, good catch, and agree this avoids confusion