feat: update lint workflow to use 'main' branch and enhance README with usage examples and features

Author: spiegel-im-spiegel

.github/workflows/lint.yml

@@ -2,7 +2,7 @@ name: lint
 on:
   push:
     branches:
-      - master
+      - main
   pull_request:
 
 permissions:

README.md

@@ -1,2 +1,85 @@
-# webinfo
-Extract metadata and structured information from web pages
+# webinfo -- Extract metadata and structured information from web pages
+
+[![lint status](https://github.com/goark/webinfo/workflows/lint/badge.svg)](https://github.com/goark/webinfo/actions)
+[![GitHub license](https://img.shields.io/badge/license-Apache%202-blue.svg)](https://raw.githubusercontent.com/goark/webinfo/master/LICENSE)
+[![GitHub release](http://img.shields.io/github/release/goark/webinfo.svg)](https://github.com/goark/webinfo/releases/latest)
+
+webinfo is a small Go module that extracts common metadata from web pages and provides utilities
+to download representative images and create thumbnails.
+
+**Quick overview**
+
+- **Package**: `webinfo`
+- **Repository**: `github.com/goark/webinfo`
+- **Purpose**: fetch page metadata (title, description, canonical, image, etc.) and download images
+
+**Features**
+
+- Fetch page metadata with `Fetch` (handles encodings and meta tag precedence).
+- Download an image referenced by `Webinfo.ImageURL` using `(*Webinfo).DownloadImage`.
+- Create a thumbnail from the referenced image using `(*Webinfo).DownloadThumbnail`.
+
+**Install**
+
+Use Go modules (Go 1.25+ as used by the project):
+
+```bash
+go get github.com/goark/webinfo@latest
+```
+
+**Basic usage**
+
+Example showing fetch and download thumbnail (error handling omitted for brevity):
+
+```go
+package main
+
+import (
+    "context"
+    "fmt"
+    "github.com/goark/webinfo"
+)
+
+func main() {
+    ctx := context.Background()
+    // Fetch metadata for a page (empty UA uses default)
+    info, err := webinfo.Fetch(ctx, "https://example.com", "")
+    if err != nil {
+        fmt.Fprintln(os.Stderr, "error fetching webinfo:", err)
+        panic(err)
+    }
+
+    // Download thumbnail: width 150, to directory "thumbnails", permanent file
+    thumbPath, err := info.DownloadThumbnail(ctx, "thumbnails", 150, false)
+    if err != nil {
+        panic(err)
+    }
+    fmt.Println("thumbnail saved:", thumbPath)
+}
+```
+
+**API notes**
+
+- `Fetch(ctx, url, userAgent)` — Parse and extract metadata. Pass an empty userAgent to use the module default.
+- `(*Webinfo).DownloadImage(ctx, destDir, temporary)` — Download the image in `Webinfo.ImageURL` and save it. If
+  `temporary` is true (or `destDir` is empty), a temporary file is created.
+- `(*Webinfo).DownloadThumbnail(ctx, destDir, width, temporary)` — Download the referenced image and produce a
+  thumbnail resized to `width` pixels (height is preserved by aspect ratio). If `destDir` is empty the method
+  creates a temporary file; when `temporary` is false the thumbnail file is named based on the original image
+  name with `-thums` appended before the extension.
+
+**Error handling**
+
+The package uses `github.com/goark/errs` for wrapping errors with contextual keys (e.g. `url`, `path`, `dir`).
+Callers should inspect returned errors accordingly.
+
+**Tests & development**
+
+- Run all tests: `go test ./...`
+- The repository includes `Taskfile.yml` tasks for common workflows; see that file for CI/test commands.
+
+## Modules Requirement Graph
+
+[![dependency.png](./dependency.png)](./dependency.png)
+
+[webinfo]: https://github.com/goark/webinfo "goark/webinfo: Extract metadata and structured information from web pages"