Introduce new, Hugo templates based, website (#713)

* Add new hugo-based website for hawkBit

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Fix broken links + wordings
- , i.e. -> i.e,
- , e.g. -> e.g.,
- hawkbit -> hawkBit
- don't -> do not
- isn't -> is not

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Remove old documentation and add maven integration

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Add Intellij files to ignore

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Update README

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Update Copyright header
* exclude website artifacts

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Harmonize usage of i.e. and e.g.

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Add remark for windows user

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Fix indention

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Introduce review findings

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Change image in 'run hawkbit' guide

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

docs/content/concepts/rollout-management.md

@@ -0,0 +1,49 @@
+---
+title: Rollout Management
+parent: Concepts
+weight: 54
+---
+
+Software update operations in large scale IoT scenarios with hundreds of thousands of devices require special handling.
+<!--more-->
+
+That includes:
+- _Technical Scalability_ by means of horizontal scale of the hawkBit server cluster in the cloud.
+- _Global_ artifact _content delivery_ capacities.
+- _Functional Scalability_ by means of:
+  - Secure handling of large volumes of devices at rollout creation time.
+  - Monitoring of the rollout progress.
+  - Emergency rollout shutdown in case of problems on to many devices.
+
+- Reporting capabilities for a complete understanding of the rollout progress at each point in time.
+
+Eclipse hawkBit sees these capabilities under the term Rollout Management.
+
+The following capabilities are currently supported by the _Rollout Management_:
+- Create, update and start of rollouts.
+  - Selection of targets as input for the rollout based on _target filter_ functionality.
+  - Selection of a _DistributionSet_.
+  - Auto-splitting of the input target list into a defined number deployment groups.
+- Approval workflow
+  - Has to be enabled explicitly in configuration.
+  - Enables a workflow that requires a user with adequate permissions to review any new or updated rollout before it 
+  can be started.
+  - Allows integration with 3rd party workflow engines.
+  
+- Cascading start of the deployment groups based on installation status of the previous group.
+- Emergency shutdown of the rollout in case a group exceeds the defined error threshold.
+- Rollout progress monitoring for the entire rollout and the individual groups.
+
+
+## Cascading Deployment Group Execution
+The cascading execution of the deployment groups is based on two thresholds that can be defined by the rollout creator.
+- success condition by means of percentage of successfully installed targets in the current groups triggers.
+- error condition by means of absolute or percentage of failed installations which triggers an emergency shutdown of the entire rollout.
+
+## Rollout state machine
+
+### State Machine on Rollout
+![](../../images/rolloutstatediagram.png)
+
+### State Machine on Rollout Deployment Group
+![](../../images/rolloutgroupstatediagram.png)