📖 Adds kustomize substitutions for vSphere (kubernetes-sigs#7517)

* Adds kustomize subs fopr vSphere

Signed-off-by: Sagar Muchhal <[email protected]>

* Update docs/book/src/developer/tilt.md

Co-authored-by: Stefan Büringer <[email protected]>

Signed-off-by: Sagar Muchhal <[email protected]>
Co-authored-by: Stefan Büringer <[email protected]>

Author: srm09

docs/book/src/developer/tilt.md

@@ -100,7 +100,7 @@ kustomize_substitutions:
   EXP_RUNTIME_SDK: "true"
 ```
 
-{{#tabs name:"tab-tilt-kustomize-substitution" tabs:"AWS,Azure,DigitalOcean,GCP"}}
+{{#tabs name:"tab-tilt-kustomize-substitution" tabs:"AWS,Azure,DigitalOcean,GCP,vSphere"}}
 {{#tab AWS}}
 
 For example, if the yaml contains `${AWS_B64ENCODED_CREDENTIALS}`, you could do the following:
@@ -169,6 +169,15 @@ kustomize_substitutions:
   GCP_B64ENCODED_CREDENTIALS: "your credentials here"
 ```
 
+{{#/tab }}
+{{#tab vSphere}}
+
+```yaml
+kustomize_substitutions:
+  VSPHERE_USERNAME: "[email protected]"
+  VSPHERE_PASSWORD: "Admin123"
+```
+
 {{#/tab }}
 {{#/tabs }}