Emacs: pulsar version 0.2.0

Pulsar is a small package that temporarily highlights the current line, either on demand or automatically after invoking a function that is present in a user-defined list. Watch the demo and consult the manual for the technicalities. That page also includes links to the GitLab repo and its mirror on GitHub.

Below are the release notes.

Version 0.2.0 on 2022-03-16

Fixed an inconsistency that was present when Emacs was running in a server-client model where the highlight would never pulse but instead remain fixed in place until another command was invoked. By default, the pulse effect should now work for that use-case. Thanks to Mark Barton, Petter Storvik, and user kb for their feedback in issue 1: https://gitlab.com/protesilaos/pulsar/-/issues/1.
Implemented the pulsar-highlight-line command and abstracted the relevant code. Unlike pulsar-pulse-line, it never pulses the current line. Instead it keeps the highlight in place until another command is invoked. Thanks to Mark Barton for proposing this in issue 1.
Introduced the user option pulsar-pulse which determines whether pulsar should use a pulse effect (notwithstanding the aforementioned new command). When its value is non-nil (the default) pulsing takes place. Thanks to Petter Storvik for suggesting this approach in issue 1.
Added the user option pulsar-iterations which controls how smooth or abrupt the pulse effect is. This complements the existing variable pulsar-delay. Both apply only when pulsar-pulse is non-nil.
Wrote the pulsar-generic face and made it the default value of the pulsar-face user option. This is consistent with the original design of a theme-agnostic presentation, though now it ensures that the :extend attribute is used to stretch the highlight to the edge of the window (without it and depending on the theme, the highlight would only reach the last character on the line).
Updated the manual to reflect those changes.