chore(docs): Update misleading build target documentation (#3915)

Author: RicardoVaranda

docs/documentation/build.md

@@ -4,9 +4,25 @@
 `ng build` compiles the application into an output directory
 
 ## Options
-`--target` (`-t`, `-dev`, `prod`) define the build target
+`--target` (`-t`) define the build target
 
-`--environment` (`-e`)
+`--environment` (`-e`) defines the build environment
+
+`--prod` flag to set build target and environment to production
+
+`--dev` flag to set build target and environment to development
+
+```bash
+# these are equivalent
+--target=production --environment=prod
+--prod --env=prod
+--prod
+# and so are these
+--target=development --environment=dev
+--dev --e=dev
+--dev
+ng build
+```
 
 `--output-path` (`-o`) path where output will be placed
 
@@ -16,4 +32,4 @@
 
 `--base-href` (`-bh`) base url for the application being built
 
-`--aot` flag whether to build using Ahead of Time compilation
+`--aot` flag whether to build using Ahead of Time compilation