Update URLs for import into DevSite

[rszper]

• Add code tags to URLs that are examples and aren't meant to resolve. Currently, when imported to DevSite, these URLs are turned into links. The code tags make them examples instead of links.
• Fix broken neo4j link.
• Minor text updates.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 45.09%. Comparing base (97e7640) to head (ceabdab).
Report is 12 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##               main    #1974    +/-   ##
==========================================
  Coverage     45.08%   45.09%            
- Complexity     3608     3936   +328     
==========================================
  Files           835      835            
  Lines         49693    49703    +10     
  Branches       5230     5232     +2     
==========================================
+ Hits          22406    22415     +9     
- Misses        25620    25622     +2     
+ Partials       1667     1666     -1     

Components	Coverage Δ
spanner-templates	66.27% <ø> (+0.02%)	⬆️
spanner-import-export	64.20% <ø> (+0.02%)	⬆️
spanner-live-forward-migration	76.18% <ø> (ø)
spanner-live-reverse-replication	76.54% <ø> (ø)
spanner-bulk-migration	85.57% <ø> (+0.01%)	⬆️

Files with missing lines	Coverage Δ
.../google/cloud/teleport/spanner/ExportPipeline.java	0.00% <ø> (ø)
.../google/cloud/teleport/spanner/ImportPipeline.java	0.00% <ø> (ø)
...gle/cloud/teleport/spanner/TextImportPipeline.java	0.00% <ø> (ø)
...leport/templates/SpannerVectorEmbeddingExport.java	0.00% <ø> (ø)
...d/teleport/templates/common/DatadogConverters.java	81.25% <ø> (ø)
...d/teleport/templates/common/SpannerConverters.java	76.92% <ø> (ø)
...ud/teleport/v2/templates/DataStreamToBigQuery.java	0.00% <ø> (ø)
...ud/teleport/v2/templates/DataStreamToPostgres.java	0.00% <ø> (ø)
...oud/teleport/v2/templates/DataStreamToSpanner.java	9.40% <ø> (ø)
...e/cloud/teleport/v2/templates/DataStreamToSQL.java	4.68% <ø> (ø)
... and 1 more

... and 6 files with indirect coverage changes