fix: move 2u repos list out of code. added comments

repo.sh

@@ -75,8 +75,15 @@ non_release_ssh_repos=(
     "[email protected]:openedx/frontend-app-profile.git"
     "[email protected]:openedx/frontend-app-ora-grading.git"
 )
-# Space separated list of repos that use 2u specific branch
-twou_main_repos="ecommerce yourownrepo"
+# Space separated list of repos that use 2u specific branch should be
+# set in your environment. example:
+# export TWOU_MAIN_REPOS="ecommerce yourownrepo"
+#
+# If TWOU_MAIN_REPOS is set in the env, then TWOU_CHECKOUT_BRANCH must
+# also be set. Here is an example of how to update your bashrc
+# file, so that you can get these variables created (note, TWOU_MAIN_REPOS
+# likely will grow over time, and not just use ecommerce'):
+# $ echo -e "\nexport TWOU_CHECKOUT_BRANCH=\"2u/main\"\nexport TWOU_MAIN_REPOS=\"ecommerce yourownrepo\"" >> ~/.bash_profile
 
 if [ -n "${OPENEDX_RELEASE}" ]; then
     OPENEDX_GIT_BRANCH=open-release/${OPENEDX_RELEASE}
@@ -135,14 +142,14 @@ _clone ()
             _checkout_and_update_branch
             cd ..
         else
-            if [ -n "${TWOU_CHECKOUT_BRANCH}" ] && echo "${twou_main_repos}" | grep -o "${name}"; then
+            if [ -n "${TWOU_CHECKOUT_BRANCH}" ] && echo "${TWOU_MAIN_REPOS}" | grep -o "${name}"; then
                 CLONE_BRANCH="-b ${TWOU_CHECKOUT_BRANCH}"
             elif [ -n "${OPENEDX_GIT_BRANCH:-}" ]; then
                 CLONE_BRANCH="-b ${OPENEDX_GIT_BRANCH}"
             else
                 CLONE_BRANCH=""
             fi
-            echo "CLONE_BRANCH is ${CLONE_BRANCH}"
+
             if [ "${SHALLOW_CLONE}" == "1" ]; then
                 git clone ${CLONE_BRANCH} -c core.symlinks=true --depth=1 "${repo}"
             else
@@ -158,7 +165,7 @@ _checkout_and_update_branch ()
     GIT_SYMBOLIC_REF="$(git symbolic-ref HEAD 2>/dev/null)"
     BRANCH_NAME=${GIT_SYMBOLIC_REF##refs/heads/}
 
-    if [ -n "${TWOU_CHECKOUT_BRANCH}" ] && echo "${twou_main_repos}" | grep -o "${name}"; then
+    if [ -n "${TWOU_CHECKOUT_BRANCH}" ] && echo "${TWOU_MAIN_REPOS}" | grep -o "${name}"; then
         CHECKOUT_BRANCH="${TWOU_CHECKOUT_BRANCH}"
     elif [ -n "${OPENEDX_GIT_BRANCH}" ]; then
         CHECKOUT_BRANCH=${OPENEDX_GIT_BRANCH}