added workflow for updating citation

.github/workflows/update-citation.yml

@@ -0,0 +1,60 @@
+name: Update Citation Files
+
+on:
+  push:
+    paths:
+      - "DESCRIPTION"
+  workflow_dispatch:
+
+jobs:
+  update-citation:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Set up R
+        uses: r-lib/actions/setup-r@v2
+
+      - name: Install dependencies
+        run: |
+          Rscript -e 'install.packages(c("usethis", "cffr", "desc"))'
+
+      - name: Update inst/CITATION
+        run: |
+          Rscript -e '
+          library(desc);
+          # Read package metadata
+          package_title <- desc::desc_get("Title")
+          authors <- desc::desc_get("Authors@R")
+          version <- desc::desc_get("Version")
+          url <- desc::desc_get("URL")
+          year <- format(Sys.Date(), "%Y")  # Get current year
+
+          # Generate citation content dynamically
+          citation_text <- sprintf("citHeader(\"To cite this package, use:\")\n\n
+          bibentry(\n
+            bibtype = \"Manual\",\n
+            title = \"%s\",\n
+            author = %s,\n
+            year = \"%s\",\n
+            note = \"R package version %s\",\n
+            url = \"%s\"
+          )", package_title, authors, year, version, url)
+
+          # Write the updated citation file
+          writeLines(citation_text, "inst/CITATION")'
+
+
+      - name: Update CITATION.cff
+        run: |
+          Rscript -e 'cffr::cff_write()'
+
+      - name: Commit and Push if Changed
+        run: |
+          git config --global user.name "github-actions"
+          git config --global user.email "github-actions@github.com"
+          git add inst/CITATION CITATION.cff
+          git commit -m "Auto-update citation files" || echo "No changes to commit"
+          git push