doc: edit BUILDING.md

I should have done this a few days ago so it could land in time for Code
& Learn, but oh well. Here are some revisions to BUILDING.md to try to
make it easier to read.

PR-URL: #23435
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: George Adams <george.adams@uk.ibm.com>

BUILDING.md

@@ -52,8 +52,7 @@ which it is attached.
 
 ### Input
 
-Node.js relies on V8 and libuv. Therefore, we adopt a subset of their
-supported platforms.
+Node.js relies on V8 and libuv. We adopt a subset of their supported platforms.
 
 ### Strategy
 
@@ -111,8 +110,8 @@ platforms in production.
   community will only address issues that reproduce on native GNU/Linux
   systems. Issues that only reproduce on WSL should be reported in the
   [WSL issue tracker](https://github.com/Microsoft/WSL/issues). Running the
-  Windows binary (`node.exe`) in WSL is not recommended, and will not work
-  without adjustment (such as stdio redirection).
+  Windows binary (`node.exe`) in WSL is not recommended. It will not work
+  without workarounds such as stdio redirection.
 
 ### Supported toolchains
 
@@ -144,10 +143,8 @@ Otherwise `configure` will fail with an error. This can be avoided by
 either providing a newer assembler as per the list above or by
 using the `--openssl-no-asm` flag.
 
-*Note:* The forthcoming OpenSSL-1.1.1 will require higher
- version. Please refer
- https://www.openssl.org/docs/man1.1.1/man3/OPENSSL_ia32cap.html for
- details.
+The forthcoming OpenSSL-1.1.1 will have different requirements. Please refer to
+ https://www.openssl.org/docs/man1.1.1/man3/OPENSSL_ia32cap.html for details.
 
 ## Building Node.js on supported platforms
 
@@ -216,7 +213,7 @@ $ make test-only
 
 At this point, you are ready to make code changes and re-run the tests.
 
-If you are running tests prior to submitting a Pull Request, the recommended
+If you are running tests before submitting a Pull Request, the recommended
 command is:
 
 ```console
@@ -344,7 +341,7 @@ Prerequisites:
   and tools which can be included in the global `PATH`.
 * The [NetWide Assembler](http://www.nasm.us/), for OpenSSL assembler modules.
   If not installed in the default location, it needs to be manually added
-  to `PATH`. Build with `openssl-no-asm` option does not require this.
+  to `PATH`. A build with the `openssl-no-asm` option does not need this.
 * **Optional** (to build the MSI): the [WiX Toolset v3.11](http://wixtoolset.org/releases/)
   and the [Wix Toolset Visual Studio 2017 Extension](https://marketplace.visualstudio.com/items?itemName=RobMensching.WixToolsetVisualStudio2017Extension).
 
@@ -369,12 +366,10 @@ To test if Node.js was built correctly:
 
 ### Android/Android-based devices (e.g. Firefox OS)
 
-Although these instructions for building on Android are provided, please note
-that Android is not an officially supported platform at this time. Patches to
-improve the Android build are accepted. However, there is no testing on Android
-in the current continuous integration environment. The participation of people
-dedicated and determined to improve Android building, testing, and support is
-encouraged.
+Android is not a supported platform. Patches to improve the Android build are
+welcome. There is no testing on Android in the current continuous integration
+environment. The participation of people dedicated and determined to improve
+Android building, testing, and support is encouraged.
 
 Be sure you have downloaded and extracted
 [Android NDK](https://developer.android.com/tools/sdk/ndk/index.html) before in