ci: fix generate epub

Author: SergioRibera

.github/workflows/main.yml

@@ -97,7 +97,7 @@ jobs:
         mdbook build
         cargo run --bin lfp src
     - name: Run epub backend
-      run: mdbook-epub --standalone true
+      run: mdbook-epub --standalone .
     - name: Validate references
       run: bash ci/validate.sh
     - name: Check for broken links

.github/workflows/pr-preview.yml

@@ -72,7 +72,7 @@ jobs:
       - name: Build with mdBook
         run: mdbook build
       - name: Build with mdBook-epub
-        run:  mdbook-epub --standalone true
+        run:  mdbook-epub --standalone .
 
       # Deploy
       - name: Deploy