docs(reference): Update overview.md

- Remove duplicate lines in the overview.md file
- Fix formatting issues in the overview.md file
- Fix broken image links in the processors section
- Update the tables headers

Author: Kellian Leveque

docs/reference/overview.md

@@ -3,8 +3,6 @@
 This project aims to offer a range of tools to promote greener computing. The focus is on creating software-defined PowerMeters to measure the power consumption of various programs.  
 At the heart of this initiative is the [PowerAPI](https://github.com/powerapi-ng/powerapi) toolkit, which facilitates the development of these PowerMeters.
 
-
-
 ## Software PowerMeters
 
 A software PowerMeter is an application built using PowerAPI components, designed to measure the power consumption of software running on a single machine or across a cluster of machines.
@@ -13,10 +11,10 @@ The diagram below illustrates the overall architecture of a PowerMeter within th
 
 ![PowerAPI Architecture Overview](../assets/images/reference/overview/global-architecture.jpg){ width="1000px"}
 
-A PowerMeter consists of two essential components:  
+A PowerMeter consists of two essential components:   
 
-- A [Sensor](#Sensor), which collects system usage metrics and generates usage reports.  
-- A [Formula](#Formula), which applies a computational model to the usage reports, producing power consumption data (in mJ).  
+- a [Sensor](#Sensor), which collects system usage metrics and generates usage reports.  
+- a [Formula](#Formula), which applies a computational model to the usage reports, producing power consumption data (in mJ).
 
 Additionally, [Preprocessors](./overview.md#Preprocessors) can be utilized to modify usage reports before they are processed by the Formula.
 
@@ -30,9 +28,9 @@ The raw data collected is then stored as usage Reports in various formats, eithe
 
 ### Existing Sensors
 
-| Sensor name | Documentation | GitHub Repository | Description | Supported |
+| Sensor | Documentation | Repository | Description | Supported |
 | :---------------: |----------------------|--------------------------|----------------|---------------|
-| HWPC            | [HWPC Documentation](./sensors/hwpc-sensor.md) | https://github.com/powerapi-ng/hwpc-sensor | Hardware Performance Counters monitoring agent for containers |  :material-check: Supported |
+| HWPC            | [HWPC Documentation](./sensors/hwpc-sensor.md) | [Github](https://github.com/powerapi-ng/hwpc-sensor) | Hardware Performance Counters monitoring agent for containers |  :material-check: Supported |
 
 
 ## Formula
@@ -47,17 +45,17 @@ There are two modes in which a Formula can operate:
 
 ### Existing Formulas
 
-| Formula name | Documentation | GitHub Repository | Description | Supported |
+| Formula | Documentation | Repository | Description | Supported |
 | :---------------: |----------------------|--------------------------|----------------|---------------|
-| SmartWatts            | [SmartWatts Documentation](./formulas/smatwatts.md) | https://github.com/powerapi-ng/smartwatts-formula | HSmartWatts is a formula for a self-adaptive software-defined power meter based on the PowerAPI framework.  |  :material-check: Supported |
+| SmartWatts            | [SmartWatts Documentation](./formulas/smatwatts.md) | [Github](https://github.com/powerapi-ng/smartwatts-formula) | HSmartWatts is a formula for a self-adaptive software-defined power meter based on the PowerAPI framework.  |  :material-check: Supported |
 
 ## Processors
 
 Processors allow for the customized filtering and modification of Reports. While optional, they offer additional flexibility, but Software PowerMeters can still function without them.
 
 The diagram below shows where Processors are integrated into the architecture of a Software PowerMeter.
 
-![Processor integration in the processing pipeline](../..//docs/assets/images/reference/processors/processors.jpg)
+![Processor integration in the processing pipeline](../assets/images/reference/processors/processors.jpg)
 
 ### Preprocessors
 
@@ -66,8 +64,8 @@ Their role is to pre-process usage reports before the power consumption estimati
 
 #### Existing Preprocessors
 
-| Preprocessor name | Documentation | GitHub Repository | Description | Supported |
+| Preprocessor | Documentation | Repository | Description | Supported |
 | :---------------: |----------------------|--------------------------|----------------|---------------|
-| k8sPreprocessor            | [k8sPreprocessor Documentation](./processors/processors.md#k8spreprocessor) | https://github.com/powerapi-ng/powerapi/tree/master/src/powerapi/processor/pre/k8s | Add K8S Specific metadata to corresponding Reports |  :material-check: Supported |
-| libvirt | [libvirtPreprocessor Documentation](.processors/processors.md#libvirt) | https://github.com/powerapi-ng/powerapi/tree/master/src/powerapi/processor/pre/libvirt | Replace `libvirt ID` in Reports with `Open Stack UUID` | :material-check: Supported |
+| k8sPreprocessor            | [k8sPreprocessor Documentation](./processors/processors.md#k8spreprocessor) | [Github](https://github.com/powerapi-ng/powerapi/tree/master/src/powerapi/processor/pre/k8s) | Add K8S Specific metadata to corresponding Reports |  :material-check: Supported |
+| libvirt | [libvirtPreprocessor Documentation](.processors/processors.md#libvirt) | [Github](https://github.com/powerapi-ng/powerapi/tree/master/src/powerapi/processor/pre/libvirt) | Replace `libvirt ID` in Reports with `Open Stack UUID` | :material-check: Supported |