github/workflows: use <year>.<month>.<day>.<hour> as version

Marketplace does not allow prerelease annotation.
That caused the release error like
https://github.com/golang/vscode-go/runs/517074211?check_suite_focus=true

Use the four digit semver instead. Note the current `vsce package`
command allows prerelease annotation but does not allow four digit
semver format currently.

And record the commit hash to the CHANGELOG.md
since we cannot rely on the version string to encode the info.

Update #5

Change-Id: Id45fc822bb0d5b6b6750e28bf71bbb49f3eb97be
GitHub-Last-Rev: cf71291
GitHub-Pull-Request: #12
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/223961
Reviewed-by: Rebecca Stambler <[email protected]>

Author: hyangah

build/all.bash

@@ -52,7 +52,8 @@ run_test_in_docker() {
 }
 
 prepare_nightly() {
-  local VER=`git log -1 --format=%cd-%h --date="format:%Y.%-m.%-d"`
+  local VER=`git log -1 --format=%cd --date="format:%Y.%-m.%-d.%-H"`
+  local COMMIT=`git log -1 --format=%H`
   echo "**** Preparing nightly release : $VER ***"
 
   # Update package.json
@@ -68,7 +69,8 @@ prepare_nightly() {
 .bugs.url="https://github.com/golang/vscode-go/issues"
 ') > /tmp/package.json && mv /tmp/package.json package.json
 
-  # TODO(hyangah): Update README.md and CHANGELOG.md
+  # TODO(hyangah): Update README.md
+  echo "**Release ${VER} @ ${COMMIT}** " | cat - CHANGELOG.md > /tmp/CHANGELOG.md.new && mv /tmp/CHANGELOG.md.new CHANGELOG.md
 }
 
 main() {