Merge branch 'documentation/#5' into 'develop'

You can leave the Alias and Unit of Measure as is. Check also the is Default.

### OSM NS LCM Status

When a Service is deployed, OpenSlice provides the ability to see the status messages from the NFVO. This status can be regarding NS instantiation, primitive execution, etc.

Going to `ResourceFacingService (RFS)` -> `Contextual Features` -> `MANO NSLCM`, you will be able to see a beautified view of the status messages retrieved by OSM.

<img src="../images/catalogs/mano_nslcm.png" alt="MANO NSLCM Section" width="700"/>

### Day 2 Primitive Actions

NFVOs like OSM allow to perform actions while a service is running, for example change attributes or make actions on a specific VNF. To design this do something similar to the following example:

NFVOs like OSM allow to perform actions while a service is running, for example change attributes or make actions on a specific VNF.

OpenSlice supports the invocation of day 2 primitives using Open Source MANO (OSM). This feature allows users to perform various actions while a service is running, such as changing attributes or executing specific actions on a Network Service's (NSD) Virtual Network Function (VNF). This capability enhances the flexibility and control over network services, making it easier to manage them in real-time.

#### Invoking Primitives in OpenSlice

To design and invoke primitives in OpenSlice, do the following steps:

1. When a service is instantiated, go to its `ResourceFacingService (RFS)` -> `Contextual Features` -> `MANO Primitives List`;

    <img src="../images/catalogs/mano_primitives_list.png" alt="MANO Primitives List Section" width="700"/>

2. There, you will find that VNF available primitives;

3. Click on the `Execute Primitive` button of the chosen VNF;

4. On the `Execute MANO Primitives` window:

    1. Select the desired primitive on the `Primitive Parameter Name`;

    2. Provide the `Primitive Parameter Value`;

        <img src="../images/catalogs/execute_mano_primitives.png" alt="Execute MANO Primitives Window" width="500"/>

5. Click on the `Submit` button.

-	Go to the RFS related to the NSD that contains VNFs with primitives

-	create a characteristic named Primitive::<primitive> , e.g. Primitive::touch

-	select Value Type: ARRAY

-	add Service Characteristic Value: i) alias=primitive, value=<primitivename> (e.g. touch), ii)  alias=member_vnf_index, value=<vnf index> (e.g. 1), iii) add the params that the user will change in alias the name of param and in value an initial value (e.g. alias=filename, value=myfile.txt)

After the previous steps, after a while, you should be able to see the status of the primitive execution above on the same page, on the `MANO NSLCM` section.

In the above example, when the service is running and the user goes to service inventory to MODIFY it, changes the value of the alias=filename, value=myfile.txt, to value =secondfile.txt. Then inside the VNF a file will be created called secondfile.txt

> ***IMPORTANT NOTE:***

As of now, OpenSlice still only supports the invoking of VNF-level primitives. We expect to have VDU-level primitives in the future.