Add package-level help page and pkgdown reference grouping

Improves discoverability of the now-16 exported functions:
- New ?svyTable1 package-level help page (R/svyTable1-package.R) that groups the
  functions by purpose (survey design, descriptive tables, model diagnostics,
  interaction analysis, survival analysis, multiple imputation, data).
- _pkgdown.yml gains a matching reference index with the same groupings, and the
  site URL is given a trailing slash.

No code or dependency changes; R CMD check unaffected.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: ehsanx

R/svyTable1-package.R

@@ -0,0 +1,55 @@
+#' svyTable1: Survey-Weighted Tables and Diagnostics for Epidemiology
+#'
+#' @description
+#' A teaching toolkit for analyzing complex survey data (such as 'NHANES'). The
+#' exported functions are organized into the following groups.
+#'
+#' @section Survey design:
+#' \itemize{
+#'   \item \code{\link{svydesign_build}}: build a survey design from plain column
+#'     names, with input validation and correct subpopulation handling.
+#' }
+#'
+#' @section Descriptive tables:
+#' \itemize{
+#'   \item \code{\link{svytable1}}: survey-weighted "Table 1" with optional NCHS
+#'     reliability suppression.
+#' }
+#'
+#' @section Model diagnostics:
+#' \itemize{
+#'   \item \code{\link{svydiag}}: per-coefficient reliability diagnostics.
+#'   \item \code{\link{svygof}}: Archer-Lemeshow goodness-of-fit test.
+#'   \item \code{\link{svyAUC}}: design-correct AUC.
+#' }
+#'
+#' @section Interaction analysis:
+#' \itemize{
+#'   \item \code{\link{addint}}, \code{\link{addintlist}}: additive interaction
+#'     (RERI, AP, S).
+#'   \item \code{\link{jointeffects}}, \code{\link{inteffects}}: joint and simple
+#'     (stratum-specific) effects.
+#'   \item \code{\link{reportint}}: multi-panel interaction report.
+#'   \item \code{\link{plotint}}: interaction plots for continuous moderators.
+#' }
+#'
+#' @section Survival analysis:
+#' \itemize{
+#'   \item \code{\link{svykmplot}}: survey-weighted Kaplan-Meier plots.
+#'   \item \code{\link{svycoxph_CE}}, \code{\link{svycoxph_CE_mi}}:
+#'     constant-effect / proportional-hazards diagnostics.
+#' }
+#'
+#' @section Multiple imputation:
+#' \itemize{
+#'   \item \code{\link{svypooled}}: fallacy-safe pooled tables from \pkg{mice}.
+#' }
+#'
+#' @section Data:
+#' \itemize{
+#'   \item \code{\link{nhanes_mortality}}: bundled NHANES mortality cohort used
+#'     throughout the examples and vignettes.
+#' }
+#'
+#' @keywords internal
+"_PACKAGE"

_pkgdown.yml

@@ -1,4 +1,42 @@
-url: https://ehsanx.github.io/svyTable1
+url: https://ehsanx.github.io/svyTable1/
 template:
   bootstrap: 5
 
+reference:
+- title: Survey design
+  desc: Build and validate a complex-survey design.
+  contents:
+  - svydesign_build
+- title: Descriptive tables
+  desc: Survey-weighted "Table 1" summaries.
+  contents:
+  - svytable1
+- title: Model diagnostics
+  desc: Assess reliability, fit, and discrimination of survey regression models.
+  contents:
+  - svydiag
+  - svygof
+  - svyAUC
+- title: Interaction analysis
+  desc: Additive interaction, joint and simple effects, and interaction reports.
+  contents:
+  - addint
+  - addintlist
+  - jointeffects
+  - inteffects
+  - reportint
+  - plotint
+- title: Survival analysis
+  desc: Survey-weighted Kaplan-Meier plots and proportional-hazards diagnostics.
+  contents:
+  - svykmplot
+  - svycoxph_CE
+  - svycoxph_CE_mi
+- title: Multiple imputation
+  desc: Pooled, fallacy-safe regression tables.
+  contents:
+  - svypooled
+- title: Data and helpers
+  contents:
+  - nhanes_mortality
+  - "%>%"