docs(nuget): rewrite, add admonitions, add headings (#18906)

docs/usage/nuget.md

@@ -59,19 +59,26 @@ You can set alternative feeds:
 
 In the example above we've set three NuGet feeds.
 The package resolving process uses the `merge` strategy to handle the three feeds.
-All feeds are checked for dependency updates, and duplicate updates are merged/joined together into a single dependency update.
+All feeds are checked for dependency updates, and duplicate updates are merged into a single dependency update.
 
-If your project uses lockfiles (a `package.lock.json` exists), alternate feed settings must be defined in a `NuGet.config` only, as `registryUrls` are not passed through to the NuGet commands used.
+<!-- prettier-ignore -->
+!!! warning
+    If your project has lockfile(s), for example a `package.lock.json` file, then you must set alternate feed settings in the `NuGet.config` file only.
+    `registryUrls` set in other files are **not** passed to the NuGet commands.
 
 ### Protocol versions
 
 NuGet supports two protocol versions, `v2` and `v3`.
 The NuGet client and server must use the same version.
+When Renovate acts as the client, it can use the `v2` and `v3` protocols.
+
+By default, Renovate uses the `v2` protocol.
+If the configured feed URL ends with `index.json`, Renovate uses the `v3` protocol.
+So Renovate behaves like the official NuGet client.
 
-Renovate as a NuGet client supports both `v2` and `v3` protocols, and will use `v2` unless the configured feed URL ends with `index.json`.
-This mirrors the behavior of the official NuGet client.
+#### v3 feed URL not ending with index.json
 
-If you have a `v3` feed that doesn't end with `index.json`, like for example on the JFrog Artifactory, then you must append `#protocolVersion=3` to the registry URL:
+If a `v3` feed URL does not end with `index.json`, you must append `#protocolVersion=3` to the registry URL:
 
 ```json
 {
@@ -81,6 +88,8 @@ If you have a `v3` feed that doesn't end with `index.json`, like for example on
 }
 ```
 
+You may need this workaround when you use the JFrog Artifactory.
+
 ## Authenticated feeds
 
 Credentials for authenticated/private feeds can be given via host rules in the configuration options (file or command line parameter).
@@ -98,12 +107,12 @@ Credentials for authenticated/private feeds can be given via host rules in the c
 }
 ```
 
-When using Azure DevOps, you can use `pkgs.dev.azure.com` as `matchHost` value.
+If you're using Azure DevOps, you can set `matchHost` to `pkgs.dev.azure.com`.
 
 <!-- prettier-ignore -->
 !!! note
     Only Basic HTTP authentication (via username and password) is supported.
-    For Azure DevOps, you can use a Personal Access Token (PAT) with read permissions on `Packaging` along with an empty username.
+    For Azure DevOps, you can use a PAT with `read` permissions on `Packaging` plus an empty username.
 
 ## Future work