Removing multiple completely yields runtime error

[g-pavlov]

What happened:
Removing multiple links completely with a rewrite rule fails with runtime error.

panic: runtime error: slice bounds out of range [:104] with capacity 64

goroutine 54 [running]:
github.com/gardener/docforge/pkg/markdown/parser.(*link).GetDestination(0xc0004180c0, 0xc0004101b7, 0x1, 0x9)
        /home/i024136/dev/docforge/pkg/markdown/parser/links.go:115 +0x8b
github.com/gardener/docforge/pkg/markdown.UpdateMarkdownLinks.func1(0xc1b180, 0xc0004180c0)
        /home/i024136/dev/docforge/pkg/markdown/links.go:79 +0xbd
github.com/gardener/docforge/pkg/markdown/parser.(*document).ListLinks(0xc000400060, 0xc00040c030)
        /home/i024136/dev/docforge/pkg/markdown/parser/document.go:15 +0x82
github.com/gardener/docforge/pkg/markdown.UpdateMarkdownLinks(0xc00040a000, 0xa9, 0x2a9, 0xc000418000, 0x0, 0xc00040a000, 0xa9, 0x2a9, 0x41)
        /home/i024136/dev/docforge/pkg/markdown/links.go:67 +0xc4
github.com/gardener/docforge/pkg/reactor.(*nodeContentProcessor).reconcileMDLinks(0xc0000bf380, 0xc15700, 0xc0000cb640, 0xc0001be3f0, 0xc00040a000, 0xa9, 0x2a9, 0xc0000a8150, 0x24, 0x0, ...)
        /home/i024136/dev/docforge/pkg/reactor/content_processor.go:104 +0xe9
github.com/gardener/docforge/pkg/reactor.(*nodeContentProcessor).ReconcileLinks(0xc0000bf380, 0xc15700, 0xc0000cb640, 0xc0001be3f0, 0xc0000a8150, 0x24, 0xc00040a000, 0xa9, 0x2a9, 0x0, ...)
        /home/i024136/dev/docforge/pkg/reactor/content_processor.go:87 +0x1cd
github.com/gardener/docforge/pkg/reactor.(*DocumentWorker).Work(0xc0001771f0, 0xc15700, 0xc0000cb640, 0xa23ce0, 0xc0000bc348, 0xc15940, 0xc0001731a0, 0x2)
        /home/i024136/dev/docforge/pkg/reactor/document_worker.go:142 +0x8ee
github.com/gardener/docforge/pkg/jobs.(*Job).startWorkers.func1(0xc00017d220, 0xc000304000, 0xc15700, 0xc0000cb640, 0x4, 0xc15940, 0xc0001731a0, 0xc000302000)
        /home/i024136/dev/docforge/pkg/jobs/jobs.go:248 +0x302
created by github.com/gardener/docforge/pkg/jobs.(*Job).startWorkers
        /home/i024136/dev/docforge/pkg/jobs/jobs.go:232 +0x115

What you expected to happen:
Links to be removed

How to reproduce it (as minimally and precisely as possible):

• manifest:

structure:
- source: /home/user/test/links.md
links:
  rewrites:
    (pulls|pull|issues|issue|wiki): ~

• markdown ( /home/user/test/links.md) with multiple links that match rewrite rule that removes them:

[a](https://github.com/gardener/documentation/wiki/Architecture)
[b](https://github.com/gardener/gardener/issues/356)
[c](https://github.com/gardener/gardener/pull/2309)

How to categorize this issue?
/kind bug
/priority critical