Update Github links in README.md through script (#132)

Follow-up change for #131 (comment) .

`branch-${CURRENT_MAJOR}.${CURRENT_MINOR}` => `branch-${NEXT_MAJOR}.${NEXT_MINOR}` in README.md

Authors:
  - Gigon Bae (https://github.com/gigony)

Approvers:
  - AJ Schmidt (https://github.com/ajschmidt8)

URL: #132

ci/release/update-version.sh

@@ -41,3 +41,4 @@ sed_runner "s#\[Version ${CURRENT_LONG_TAG}\](release_notes/v${CURRENT_LONG_TAG}
 sed_runner "s/v${CURRENT_LONG_TAG}/v${NEXT_FULL_TAG}/g" python/cucim/docs/getting_started/index.md
 sed_runner "s#cucim.kit.cuslide@${CURRENT_LONG_TAG}.so#cucim.kit.cuslide@${NEXT_FULL_TAG}.so#g" python/cucim/docs/getting_started/index.md
 sed_runner "s#cucim.kit.cuslide@${CURRENT_LONG_TAG}.so#cucim.kit.cuslide@${NEXT_FULL_TAG}.so#g" cucim.code-workspace
+sed_runner "s#branch-${CURRENT_MAJOR}.${CURRENT_MINOR}#branch-${NEXT_MAJOR}.${NEXT_MINOR}#g" README.md