tools/test: Add --all option to alias --all-files --platforms both.

And promote it in the release docs and run it in CI.

As Greg suggests:
  zulip#4700 (comment).

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
       uses: bahmutov/npm-install@v1
 
     - name: Run tools/test
-      run: TERM=dumb tools/test --all-files --platform both
+      run: TERM=dumb tools/test --all
 
     - run: tools/verify-webview-js
 

docs/howto/release.md

@@ -80,7 +80,7 @@ simple terminology for the process we follow with both.
     our translation contributors.  See
     [howto/translations.md](translations.md) for background.
 
-* Check that tests pass: `tools/test --all-files --platform both`.
+* Check that tests pass: `tools/test --all`.
 
 * Run `tools/bump-version` to update the version number in the
   Android and iOS build metadata.

tools/test

@@ -22,7 +22,7 @@ set -e
 
 usage() {
     cat >&2 <<EOF
-usage: tools/test [--all-files | --diff COMMIT] [--platform <ios|android|both|sloppy>] [SUITES]
+usage: tools/test [--all-files | --diff COMMIT] [--platform <ios|android|both|sloppy>] [--all] [SUITES]
 
 Run our tests.
 
@@ -50,6 +50,8 @@ Options:
               (E.g., \`--diff @\` for files with uncommitted changes;
               \`--diff @~10\` for files changed in last 10 commits; or see
               \`git help revisions\` for many more ways to name a commit.)
+  --all       In the given suites, run all tests on all files. Same as
+              --all-files --platforms both.
 
 Suites:
   native
@@ -82,6 +84,7 @@ while (( $# )); do
             esac
             shift
             ;;
+        --all) files=all; platform=both; shift;;
         --fix) fix=1; shift;;
         native|flow|lint|jest|prettier|deps)
             suites+=("$1"); shift;;