Update "Use Svelte in your plugin" for Svelte 4

[inhumantsar]

Note that this includes an upgrade to Typescript 5. This is working fine on my simple plugin but I'm not sure what kind of breaking changes might be lurking deeper down the stack.

Closes #92

[bhavers]

Can confirm that these changes worked for me (typescript 5 and the changes in commit). Only get a warning on compilerOptions.css. But doesn't seem to do harm.

> node esbuild.config.mjs
[watch] build finished, watching for changes...
compilerOptions.css as a boolean is deprecated. Use 'injected' instead of true.

[San7o]

These changes worked for me as well and resolved some confusion about how to add Svelte to the plugins, given that the Obsidian sample plugin code has changed ("6. Add Svelte to the list of plugins.")

[dj-sf]

@inhumantsar @hemstreet just confirming that this fixed svelte store issues that I was having as well.

[mProjectsCode]

The guide should be updated to svelte 5 as that is the newest version now. Some stuff is a lot simpler, e.g. sveltePreprocess is no longer needed.

[joethei]

Since the Svelte 5 PR was merged this is no longer needed. Thanks for your work!