Style fixes for build docker image docs

Author: Jon Glassman

doc/build/build_docker_image.md

@@ -4,35 +4,33 @@ group: Distribution
 info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/product/ux/technical-writing/#assignments
 ---
 
-# Building an all-in-one GitLab Docker image locally
+# Build a GitLab Docker image locally
 
-The GitLab all-in-one Docker image uses Ubuntu 20.04 package created by
-`omnibus-gitlab` under the hood. The files required for building Docker image
-can be found inside the `Docker` directory of `omnibus-gitlab` repository,
-except `RELEASE` file which needs to be compiled manually, as described below.
+The GitLab Docker image uses the Ubuntu 20.04 package created by
+`omnibus-gitlab`. Most of the files needed for building a Docker image
+are in the `Docker` directory of the `omnibus-gitlab` repository.
+The `RELEASE` file is not in this directory, and you must create this file.
 
-## RELEASE file
+## Create the `RELEASE` file
 
-The details of the version of the package being used is stored in a file named
-`RELEASE`. To build your own Docker image, you should create this file with
-contents similar to the following
+The version details of the package being used are stored in the `RELEASE` file.
+To build your own Docker image, create this file with contents similar to the following.
 
 ```plaintext
 RELEASE_PACKAGE=gitlab-ee
 RELEASE_VERSION=13.2.0-ee
 DOWNLOAD_URL=https://example.com/gitlab-ee_13.2.00-ee.0_amd64.deb
 ```
 
-Here, `RELEASE_PACKAGE` specifies whether the package is a CE one or EE one.
-`RELEASE_VERSION` specifies the version of the package (`13.2.0-ee`,
-`12.9.2+rfbranch.150270.c43b3273-0`, etc.). `DOWNLOAD_URL` specifies the URL
-where that package can be downloaded from.
+- `RELEASE_PACKAGE` specifies whether the package is a CE one or EE one.
+- `RELEASE_VERSION` specifies the version of the package, for example `13.2.0-ee`.
+- `DOWNLOAD_URL` specifies the URL where that package can be downloaded from.
 
 NOTE **Note:**
 We're looking at improving this situation, and using locally available packages
 [in issue #5550](https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/5550).
 
-## Building the Docker image
+## Build the Docker image
 
 To build the Docker image after populating the `RELEASE` file:
 
@@ -41,4 +39,4 @@ cd docker
 docker build -t omnibus-gitlab-image:custom .
 ```
 
-The image will be built and tagged as `omnibus-gitlab-image:custom`.
+The image is built and tagged as `omnibus-gitlab-image:custom`.