[docs] System scheduler doesn't do deployments.

docs: improve wording of linux requirement

Sunset /guide folder; Fix links 

wrap http.Handlers

better comments

(cherry picked from commit 5cb4e48571609bf391e8dc0afcf832275990f33e)

(cherry picked from commit 81298e3e5b1110a0f4d15e0641e59aee3514b059)

(cherry picked from commit 8e247ac192298ad54743a13b75c30b2572493adc)

(cherry picked from commit 624c411830a4f81232ae8e9007ba8f6b68b9f47e)

links ending with / and links without a terminal / are handled the same
according to the netlify redirect documenation

(cherry picked from commit 91171c6a1dd74e3396a66e35c27c6ec858c5977f)

(cherry picked from commit 0e39e2e49b0371c246dc1a9b4bb20af0b2f642a0)

(cherry picked from commit 575f22e970e2429b8f9871f11b8c3e0924c82dc2)

(cherry picked from commit ce9d9b5e69fe5f47847cc511ffd73f6b43de92e7)

(cherry picked from commit ac49040b9caa843fa78ef494baac3c6a08b15d45)

reparented some elements to docs.

(cherry picked from commit 4fa35e51e0e0d193bf81f4465f4e1ba4caa5b3ca)

fingerprint: handle incomplete AWS imitation APIs

* nomad/structs/csi: delete just one plugin type from a node

* nomad/structs/csi: add DeleteAlloc

* nomad/state/state_store: add deleteJobFromPlugin

* nomad/state/state_store: use DeleteAlloc not DeleteNodeType

* move CreateTestCSIPlugin to state to avoid an import cycle

* nomad/state/state_store_test: delete a plugin by deleting its jobs

* nomad/*_test: move CreateTestCSIPlugin to state

* nomad/state/state_store: update one plugin per transaction

* command/plugin_status_test: move CreateTestCSIPlugin

* nomad: csi: handle nils CSIPlugin methods, clarity

Avoid resolving dotted segments when host path for volume is named pipe

UI: Guard against a null value for the HostVolumes hash

When a node has no host volumes, the API response will
have a null value for the HostVolumes attribute, which
in turn becomes a null value instead of an empty array
in the store. This protects against that, ensuring host
volumes is always an array.

If not in use and not changing external ids, it should not be an error to register a volume again.

* nomad/state/state_store: make volume registration idempotent

Fix a regression where we accidentally started treating non-AWS
environments as AWS environments, resulting in bad networking settings.

Two factors some at play:

First, in [1], we accidentally switched the ultimate AWS test from
checking `ami-id` to `instance-id`.  This means that nomad started
treating more environments as AWS; e.g. Hetzner implements `instance-id`
but not `ami-id`.

Second, some of these environments return empty values instead of
errors!  Hetzner returns empty 200 response for `local-ipv4`, resulting
into bad networking configuration.

This change fix the situation by restoring the check to `ami-id` and
ensuring that we only set network configuration when the ip address is
not-empty.  Also, be more defensive around response whitespace input.

[1] https://github.com/hashicorp/nomad/pull/6779

Test that nomad doesn't set empty/bad network configuration when in an
environment that does incomplete immitation of EC2 Metadata API.

website: Miscellaneous cherry-picks from stable-website that was accidentally never pushed to master