feat: kong cli refactor fixes #1955 (#1974)

* feat: migrate to alecthomas/kong for CLI

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* feat: bring in new flag for granular log levels

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* chore: go mod tidy

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* feat: allow loading cli flag values from ["./localai.yaml", "~/.config/localai.yaml", "/etc/localai.yaml"] in that order

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* feat: load from .env file instead of a yaml file

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* feat: better loading for environment files

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* feat(doc): add initial documentation about configuration

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* fix: remove test log lines

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* feat: integrate new documentation into existing pages

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* feat: add documentation on .env files

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* fix: cleanup some documentation table errors

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

* feat: refactor CLI logic out to it's own package under core/cli

Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>

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Signed-off-by: Chris Jowett <421501+cryptk@users.noreply.github.com>