Problem: installing gitdown in ~/bin does not work on GH Actions

Solution: install in the working directory

Author: bluca

Diff for: builds/check_readme/ci_build.sh

@@ -31,11 +31,8 @@ rm -rf tmp-deps
 mkdir tmp-deps
 
 echo "=== Install gitdown"
-mkdir -p ~/bin
 ( cd tmp-deps && git clone https://github.com/zeromq/gitdown.git gitdown ) \
-&& ( cd tmp-deps/gitdown && ./install-wrapper ~/bin ) || exit $?
-PATH="$PATH:~/bin"
-export PATH
+&& ( cd tmp-deps/gitdown && ./install-wrapper "${REPO_DIR}" ) || exit $?
 command -v gitdown >/dev/null 2>&1
 
 echo "=== Configure zproject to get a Makefile"
@@ -48,6 +45,7 @@ $CI_TIME ./configure --prefix="${BUILD_PREFIX}" || exit $?
 echo "=== Make sure zproject markdown docs are up to date"
 touch *.txt *.xml
 make README.md
+rm -f "${REPO_DIR}/gitdown"
 if [[ $(git --no-pager diff -w) ]]; then
     git --no-pager diff -w
     echo "=== FAIL: There are diffs between current README.md and the one generated by gitdown!"