Engdocs 2002: minor triage on compose issues (#19511)

* clarify base compose file meaning

* update name example and reformat link

content/compose/compose-file/04-version-and-name.md

@@ -24,11 +24,11 @@ Whenever a project name is defined by top-level `name` or by some custom mechani
 [interpolation](12-interpolation.md) and environment variable resolution as `COMPOSE_PROJECT_NAME`
 
 ```yml
+name: myapp
+
 services:
   foo:
     image: busybox
-    environment:
-      - COMPOSE_PROJECT_NAME
     command: echo "I'm running ${COMPOSE_PROJECT_NAME}"
 ```
 

content/compose/compose-file/09-secrets.md

@@ -6,7 +6,7 @@ keywords: compose, compose specification, secrets, compose file reference
 
 Secrets are a flavor of [Configs](08-configs.md) focusing on sensitive data, with specific constraint for this usage. 
 
-Services can only access secrets when explicitly granted by a [`secrets`](05-services.md#secrets) attribute within the `services` top-level element.
+Services can only access secrets when explicitly granted by a [`secrets` attribute](05-services.md#secrets) within the `services` top-level element.
 
 The top-level `secrets` declaration defines or references sensitive data that is granted to the services in your Compose
 application. The source of the secret is either `file` or `environment`.

content/compose/multiple-compose-files/extends.md

@@ -20,7 +20,7 @@ application, with the ability to override some attributes for your own needs.
 > **Important**
 >
 > When you use multiple Compose files, you must make sure all paths in the files
-are relative to the base Compose file. This is required because extend files
+are relative to the base Compose file (i.e. the Compose file in your main-project folder). This is required because extend files
 need not be valid Compose files. Extend files can contain small fragments of
 configuration. Tracking which fragment of a service is relative to which path is
 difficult and confusing, so to keep paths easier to understand, all paths must