Note I:
the exclamation-mark, it should be displayed as the last (not first) character,
this is a good way telling if the content is text aligned to the right.
Note II:
A little confusing but it seems that in GitHub,
dir="RTL" is equal to CSS' text-align:right;, (inner-text is rendered from right-to-left)
while align="right" is equal to CSS' direction:rtl;, (container is rendered from the right-side)
Note III:
As a best-practice, you should use both tag-attributes dir="RTL" and align="right" on a purely Hebrew paragraph, you can use it in DIV,P,SPAN,etc...
If you only want to include a Hebrew phrase inside a mostly English-content,
render the Hebrew content inside a SPAN with just dir="RTL", to render the content correctly.
(You can add align="right" too but in that case it is redundant).
Note IV: It seems that STYLE attributes does nothing in GitHub...
<div dir="RTL" align="right" style="direction:rtl;text-align:right;">
(תוכן!)
</div>example:
<div dir="RTL" align="right">
(תוכן!)
</div>example:
<div align="right">
(תוכן!)
</div>example:
<div dir="RTL">
(תוכן!)
</div>example:
<div style="direction:rtl;text-align:right;">
(תוכן!)
</div>example: