citekey enhancements (auto completion and more)

[osmalpkoras]

Hello,

I started using your plugin for Obsidian and found the citekey feature a little lacking, so I quickly made some enhacements:

• You can now use @"..." to search for multiple strings (seperated by the space character ) inside the reference key and title. The citekey suggestions only contain items that have a fuzzy match for all strings.
• You can now use the citekey command's (@"...") suggestions feature when it is surrounded by whitespace (of any kind) or the following characters: -, (, ), [, ], {, }
• I made modifications to the search settings to improve search results for citekey suggestions

Still To-Do:
[ ] fix displaying citekey commands when they are surrounded by the characters mentioned above (whitespace (of any kind) or the following characters: -, (, ), [, ], {, })

I was able to fix the last issue by changing the preKey variable in parser.ts:64 like this:

const preKey = /[\s()[\]{}\-;]/;

I successfully tested it on my machine. However, since I had no time to dive into how citekeys are displayed, I do not know if this fix has unwanted consequences.

[osmalpkoras]

This partly adresses issue #78

[rauchert]

@osmalpkoras thanks for your hint! I also came up with the same solution to issue #78 but actually without forking the plugin but by only replacing a character in the main.js of the plugin. See the issue...

[osmalpkoras]

Hey @mgmeyers let me know if something needs to be done for this pull request or if I can help with other issues