Graphics/vfx/fix/uum 62462 template prooread

The starter templates VFX Asset's descriptions were updated, and some changes were made to the default VFX resources:

- Fixed Typo and lousy spelling of VFX template description.
- Made a grammar and language style pass.
- Change the default Animation Curve to Linear [0-1].
-Change the Default VFX Texture to "DefaultDot.tga" so it's the same as the starter templates asset.
-Change the Default VFX Mesh to the editor Built-in Cube.fbx as it's more common and lightweight than the previous Capsule mesh.

![image](https://media.github.cds.internal.unity3d.com/user/5910/files/e1923745-dcf5-426d-a3c4-b0b10e4068a8)

Author: OrsonFavrel

Packages/com.unity.visualeffectgraph/Editor/Templates/01_Minimal_System.vfx.meta

@@ -172,12 +172,7 @@ private static void Initialize()
 
             defaultShader = Shader.Find("Shader Graphs/VFXDefault");
 
-            defaultAnimationCurve = new AnimationCurve(new Keyframe[]
-            {
-                new Keyframe(0.0f, 0.0f, 0.0f, 0.0f),
-                new Keyframe(0.25f, 0.25f, 0.0f, 0.0f),
-                new Keyframe(1.0f, 0.0f, 0.0f, 0.0f),
-            });
+            defaultAnimationCurve = AnimationCurve.Linear(0.0f, 0.0f, 1.0f, 1.0f);
 
             defaultGradient = new Gradient();
             defaultGradient.colorKeys = new GradientColorKey[]
@@ -216,7 +211,7 @@ public static Texture2D defaultParticleTexture
             get
             {
                 if (m_DefaultParticleTexture == null)
-                    m_DefaultParticleTexture = SafeLoadAssetAtPath<Texture2D>(defaultPath + "Textures/DefaultParticle.tga");
+                    m_DefaultParticleTexture = SafeLoadAssetAtPath<Texture2D>(defaultPath + "Textures/DefaultDot.tga");
                 return m_DefaultParticleTexture;
             }
         }
@@ -271,7 +266,7 @@ static public Mesh defaultMesh
             get
             {
                 if (m_DefaultMesh == null)
-                    m_DefaultMesh = Resources.GetBuiltinResource<Mesh>("New-Capsule.fbx");
+                    m_DefaultMesh = Resources.GetBuiltinResource<Mesh>("Cube.fbx");
                 return m_DefaultMesh;
             }
         }