Relative Markdown Link Completion

[fingolfin19]

Follow up to https://github.com/artempyanykh/marksman/issues/27#issuecomment-1369911689 since I do not see that a new issue was ever created.

When i start typing [title]( then absolute paths are suggested like /path-to-file.md this works fine. Also autocompletion works, when using # afterwards - like [title](/path-to-file.md# - to get a link to a header.

For relative paths both of this does not work. When typing [title](./ nothing further is being suggested by marksman. After finishing the path to an existing file and starting to type a header - like [title](./path-to-file.md# - no completions are suggested.