docs(manager/vendir): rewrite (#28755)

lib/modules/manager/vendir/readme.md

@@ -1,16 +1,21 @@
-Renovate supports updating Helm Chart references and git references in vendir.yml via the [vendir](https://carvel.dev/vendir/) tool. Renovate requires the presence of a [vendir lock file](https://carvel.dev/vendir/docs/v0.40.x/vendir-lock-spec/) which is generated by vendir and should be stored in source code.
+Renovate can update Helm Chart references and Git references in `vendir.yml` files, with the [vendir](https://carvel.dev/vendir/) tool.
+
+For Renovate to work you must:
+
+- let vendir create a [vendir lockfile](https://carvel.dev/vendir/docs/v0.40.x/vendir-lock-spec/)
+- put the vendir lockfile in your repository
 
 ### Helm Charts
 
-It supports both https and oci helm chart repositories.
+Renovate supports HTTPS and OCI Helm chart repositories.
 
 ```yaml title="Example helm chart vendir.yml"
 apiVersion: vendir.k14s.io/v1alpha1
 kind: Config
 
 # one or more directories to manage with vendir
 directories:
-  - # path is relative to `vendir` CLI working directory
+  - # path is relative to the `vendir` CLI working directory
     path: config/_ytt_lib
     contents:
       path: github.com/cloudfoundry/cf-k8s-networking
@@ -21,10 +26,10 @@ directories:
         version: '1.2.1'
         # specifies Helm repository to fetch from (optional)
         repository:
-          # repository url; supports exprimental oci helm fetch via
+          # repository url; supports experimental OCI Helm fetch via
           # oci:// scheme (required)
           url: https://...
-        # specify helm binary version to use;
+        # specify Helm binary version to use;
         # '3' means binary 'helm3' needs to be on the path (optional)
         helmVersion: '3'
 ```
@@ -33,11 +38,11 @@ directories:
 
 #### OCI
 
-Aliases for OCI registries are supported via the dockerfile/docker manager
+Aliases for OCI registries are supported via Renovate's `dockerfile` or `docker` managers.
 
 ### Git
 
-Renovates supporting explicit refs in for git references in vendir.yml
+Renovate can update explicit refs in Git references in `vendir.yml` files.
 
 ```yaml title="Example git vendir.yml"
 apiVersion: vendir.k14s.io/v1alpha1
@@ -49,7 +54,7 @@ directories:
     contents:
       path: github.com/cloudfoundry/cf-k8s-networking
       git:
-        # http or ssh urls are supported (required)
+        # HTTP or SSH URLs are supported (required)
         url: https://github.com/cloudfoundry/cf-k8s-networking
         # branch, tag, commit; origin is the name of the remote (required)
         # optional if refSelection is specified (available in v0.11.0+)
@@ -61,9 +66,9 @@ directories:
 
 ### GithubRelease
 
-Renovates supporting explicit tags in for github releases in vendir.yml
+Renovate can update explicit tags in GitHub releases in `vendir.yml` files.
 
-```yaml title="Example github vendir.yml"
+```yaml title="Example GitHub vendir.yml"
 directories:
   - path: config/_ytt_lib
     contents: