docs: overcommit-plugin enhancements

Signed-off-by: googs1025 <[email protected]>

docs/design/overcommit-plugin.md

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+# overcommit-plugin
+
+[@googs1025](https://github.com/googs1025); Jul. 29, 2024
+
+### Background: 
+The overcommit-plugin is used to amplify node resources to achieve resource allocation.
+### Objective: 
+Use different amplification factors based on different resource types.
+
+
+## Introduction
+Currently, the overcommit-plugin enhances the Allocatable resources of a node to achieve the functionality of AddJobEnqueuedFn. However, different resources should have different factors, so using the same overcommit-factor is not appropriate.
+![factor](images/overcommit-plugin.png)
+- For example:
+
+The Binpack plugin assigns different weights to different resources as well.
+
+
+```yaml
+actions: "enqueue, reclaim, allocate, backfill, preempt"
+tiers:
+- plugins:
+  - name: binpack
+    arguments:
+      binpack.weight: 10
+      binpack.cpu: 5
+      binpack.memory: 1
+      binpack.resources: nvidia.com/gpu, example.com/foo
+      binpack.resources.nvidia.com/gpu: 2
+      binpack.resources.example.com/foo: 3
+```
+
+## Solution
+We can further break down the overcommit-factor into more granular components: cpu-overcommit-factor, mem-overcommit-factor, and other-overcommit-factor.
+To maintain compatibility with the existing approach, we will retain the original overcommit-factor field and introduce optional fields for cpu-overcommit-factor, mem-overcommit-factor, and other-overcommit-factor.
+
+![factors](images/overcommit-plugin-with-multi-factors.png)
+
+The priority of these fields will be from low to high:
+
+`defaultOverCommitFactor -> overcommit-factor -> cpu-overcommit-factor, men-overcommit-factor, other overcommit-factor`
+
+
+- overcommitPlugin struct
+
+```go
+type overcommitFactors struct {
+   cpu    float64
+   memory float64
+   other  float64
+}
+
+type overcommitPlugin struct {
+   // Arguments given for the plugin
+   pluginArguments  framework.Arguments
+   totalResource    *api.Resource
+   idleResource     *api.Resource
+   inqueueResource  *api.Resource
+   overCommitFactors overcommitFactors
+}
+```
+
+#### Example
+
+Example 1:
+Specify all three values: cpu-overcommit-factor, mem-overcommit-factor, and other-overcommit-factor simultaneously.
+```yaml
+actions: "enqueue, allocate, backfill"
+tiers:
+- plugins:
+  - name: overcommit
+    arguments:
+    cpu-overcommit-factor: 1.2
+    mem-overcommit-factor: 1.0
+    other-overcommit-factor: 1.2
+```
+
+Example 2:
+Specifying only the overcommit-factor implies that all three factors are the same.
+```yaml
+actions: "enqueue, allocate, backfill"
+tiers:
+- plugins:
+  - name: overcommit
+    arguments:
+    overcommit-factor: 1.0
+```
+Example 3:
+Specifying any one of cpu-overcommit-factor, mem-overcommit-factor, or other-overcommit-factor, along with specifying overcommit-factor: indicates that the resource uses a specific value, while other values use the overcommit-factor field.
+```yaml
+actions: "enqueue, allocate, backfill"
+tiers:
+- plugins:
+  - name: overcommit
+    arguments:
+    cpu-overcommit-factor: 1.2
+    overcommit-factor: 1.0
+```
+Example 4:
+Specifying any one of cpu-overcommit-factor, mem-overcommit-factor, or other-overcommit-factor: indicates that the resource uses a specific value, while other values use the defaultOverCommitFactor default value.
+```yaml
+actions: "enqueue, allocate, backfill"
+tiers:
+- plugins:
+  - name: overcommit
+    arguments:
+    cpu-overcommit-factor: 1.2
+```
+Example 5:
+Not specifying will default to the defaultOverCommitFactor value.
+```yaml
+actions: "enqueue, allocate, backfill"
+tiers:
+- plugins:
+  - name: overcommit
+    arguments:
+```