Support of autogenerated HTML documentation via Sphinx

See merge request !7

Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>

Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>

It is already present in HSS

Changes cloud-init so that interfaces are not brought up before
netplan apply.  This allows netplan to start the dhcp client.

Added network packets to monitoring section.

Signed-off-by: beierl <mbeierl@vmware.com>

Add example content.

See merge request !5

Moves network config from charm to cloud-init so that it will
persist across reboots.

Signed-off-by: beierl <mbeierl@vmware.com>

Adds the NextEPC VNFD, NSD, charms and a build script,
Based of content from VNF Onboarding walkthrough.

Signed-off-by: beierl <mbeierl@vmware.com>

Adding notes and examples for config drive support, using --config-file, proxy charms order of operations, charm naming convention, juju deletion issue, juju charms monitoring

Minor review comments on the onboarding document

See merge request !3

Signed-off-by: Carolina Fernandez <carolina.fernandez@i2cat.net>