Refactor Request: writing the comment-tag at the start of the comment

[arieluchka-bse]

hola :)

First of all, Thanks for the extension!!!

i want to use some of the mermaid diagrams and add more to it on every sync to the PR.

right now it can easily be done by upserting to the comment with a mermaid graph (if the code block is not closed):

```mermaid
gitGraph
    commit id: "703ae9e"

Then, if we upsert to the comment:

```mermaid
gitGraph
    commit id: "703ae9e"
    commit id: "1234567"

---

The problem is, that this action leaves the comment-tag at the buttom of the comment, and then the graph fails to render

```mermaid
gitGraph
    commit id: "703ae9e"
    commit id: "1234567"

<!-- thollander/actions-comment-pull-request "git-graph" -->

Is it possible to move the tag to be written at the start of the comment?
This will open a door of possibilities to anyone who wants to dynamically generate and update those diagrams :)

example:

<!-- thollander/actions-comment-pull-request "git-graph" -->

```mermaid
gitGraph
    commit id: "703ae9e"
    commit id: "1234567"