docs: fix broken links

[rauno56]

Which problem is this PR solving?

I've managed to found many broken links usin lychee.

Short description of the changes

1. Fixed most of those links.
2. Removed links to david-dm since it really only very occasionally loads.

As much as I'd like to add lychee as a GHA, I didn't find a reliable way to do that due to the amout of links we'd be checking - GH would rate-limit us in few runs. Could potentially make it better by only checking changed md files, but figured fixing few links is already enough for now.

[codecov]

Codecov Report

Merging #945 (4b6c4d8) into main (5f63606) will decrease coverage by 3.82%.
The diff coverage is n/a.

❗ Current head 4b6c4d8 differs from pull request most recent head b6c59b1. Consider uploading reports for the commit b6c59b1 to get more accurate results

@@            Coverage Diff             @@
##             main     #945      +/-   ##
==========================================
- Coverage   95.91%   92.08%   -3.83%     
==========================================
  Files          13      125     +112     
  Lines         856     5850    +4994     
  Branches      178     1137     +959     
==========================================
+ Hits          821     5387    +4566     
- Misses         35      463     +428     

Impacted Files	Coverage Δ
...try-instrumentation-connect/src/instrumentation.ts	98.71% <0.00%> (ø)
...try-instrumentation-nestjs-core/src/enums/index.ts	100.00% <0.00%> (ø)
...nstrumentation-restify/src/enums/AttributeNames.ts	100.00% <0.00%> (ø)
...try-instrumentation-fastify/src/instrumentation.ts	97.29% <0.00%> (ø)
...try-instrumentation-ioredis/src/instrumentation.ts	91.35% <0.00%> (ø)
...ode/opentelemetry-instrumentation-dns/src/utils.ts	95.91% <0.00%> (ø)
...opentelemetry-instrumentation-restify/src/utils.ts	100.00% <0.00%> (ø)
packages/opentelemetry-host-metrics/src/util.ts	91.66% <0.00%> (ø)
...nstrumentation-express/src/enums/AttributeNames.ts	100.00% <0.00%> (ø)
...entelemetry-instrumentation-memcached/src/utils.ts	81.25% <0.00%> (ø)
... and 102 more