Footnote links to consider navbar height

[Mannisto]

Describe the bug
When clicking the footnote-links, sticky navbar height is not considered, resulting in the page landing too low. Same is true clicking the back-link from the footnote.

To Reproduce
Steps to reproduce the behavior:

1. Create a long post with a link to a footnote (by adding [1] in the post and at the end of the post putting [1]: lorem ipsum)
2. Click on the link to the footnote (1)
3. Click the back-button (↩︎) from the footnote to return to the point in the footnote (1)
4. Both locations on the page are off by the height of the navbar.

Alternatively test on my blog:

1. Go to: the footnote here
2. Scroll up the height of the navbar to see the link to the first footnote (1).
3. Click the (back-link to the text)
4. Again you must scroll up the height of the navbar to see the first footnote

Expected behavior

1. The first row of the footnote should be visible when clicking the footnote link.
2. The row linking to the footnote should be visible when clicking the "back-button ↩︎".

Desktop (please complete the following information):

• OS: Win 11
• Browser: Chrome
• Version of the Theme: latest
• Version of Hugo: hugo v0.110.0-e32a493b7826d02763c3b79623952e625402b168+extended

Smartphone (please complete the following information):

• Device: Oneplus 9 Pro
• OS: Android 15
• Browser: Chrome
• Version of the Theme: latest
• Version of Hugo: v0.110.0-e32a493b7826d02763c3b79623952e625402b168+extended