[BUG] When using lower/upper alpha in html code

[LuuPNH]

Describe the bug:

• When the html code is using the style="list-style-type:upper-alpha" to mark the required index, it gives an error.

HTML to reproduce the issue:

• Example code:

**Expected behavior:** - Fix it so I can bookmark it. -I look forward to the example code:

        A. Subscribe to calendar
        B. Hello World

Screenshots:

Device details and Flutter/Dart/flutter_html versions:

Stacktrace/Logcat

Additional info:

• I tried to use it by changing the code at package it did not report an error, but the case it handled was not normal.
• Result for my code example applying what I changed in attached image (line 791 in code):
  0. Subscribe to calendar
  0. Hello World

[erickok]

Yes I can reproduce the crash with:

<ol>
<li style="list-style-type: upper-alpha"><strong>Subscribe to calendar</strong></li>
<li style="list-style-type: upper-alpha"><strong>Hello world </strong></li>
</ol>

[erickok]

A workaround right now is to apply the list style type on the <ol> directly (or even use <ul>.

<ol style="list-style-type: upper-alpha">
<li><strong>Subscribe to calendar</strong></li>
<li><strong>Hello world </strong></li>
</ol>

But yes we need to fix this.