Add see also for add-on related entries in word list

[mheubusch]

For the following entries on the word list, please append see also the WebExtensions wiki entry. (link to https://wiki.mozilla.org/Add-ons/Terminology)

add-ons
Firefox Add-ons
Firefox Extensions
Firefox Themes
themes

[designakt]

Let's also add a reason for why people should look there?
by modifying the text to:

extension
A type of browser add-on; see also add-ons, themes and see the Add-ons Terminology wiki entry for when to use which term.

[designakt]

I've updated the entries to read as follows:

add-on

See “Firefox Add-ons”; note that “add-on” is always hyphenated, never “addon”.
See also extension and theme, and see the Add-ons Terminology wiki entry for when to use which term.

extension

A type of browser add-on; see “Firefox Extensions.”
See also theme, and see the Add-ons Terminology wiki entry for when to use which term.

theme

A type of browser add-on; see “Firefox Themes.”
See also extension, and see the Add-ons Terminology wiki entry for when to use which term.

Firefox Add-ons

Add-ons is capitalized when it follows Firefox, lowercase when on its own, though the O is always lowercase; it can be singular or plural as needed and is always localized.
See also the Add-ons Terminology wiki entry.

Firefox Extensions

Extensions is capitalized when it follows Firefox, lowercase when on its own; it can be singular or plural as needed and is always localized.
See also the Add-ons Terminology wiki entry.

Firefox Themes

Themes is capitalized when it follows Firefox, lowercase when on its own; it can be singular or plural as needed and is always localized; formerly “Firefox Personas.”
See also the Add-ons Terminology wiki entry.

https://github.com/bwinton/photon/commit/c882a6900f331b7e49b62f8b8fefc598e355195a