doc: format stars count (#281)

Use the k format for thousands, just like Github itself.

README.md

@@ -193,19 +193,19 @@ Implementations of full algorithms:
 Popular projects using `avo`:
 
 <img src="https://images.weserv.nl?fit=cover&h=24&mask=circle&maxage=7d&url=https%3A%2F%2Fgithub.com%2Fgolang.png&w=24" width="24" height="24" hspace="4" valign="middle" /> [golang / **go**](https://github.com/golang/go)
-:star: 98831
+:star: 98.8k
 > The Go programming language
 
 <img src="https://images.weserv.nl?fit=cover&h=24&mask=circle&maxage=7d&url=https%3A%2F%2Fgithub.com%2Fklauspost.png&w=24" width="24" height="24" hspace="4" valign="middle" /> [klauspost / **compress**](https://github.com/klauspost/compress)
-:star: 2894
+:star: 2.9k
 > Optimized Go Compression Packages
 
 <img src="https://images.weserv.nl?fit=cover&h=24&mask=circle&maxage=7d&url=https%3A%2F%2Fgithub.com%2Fgolang.png&w=24" width="24" height="24" hspace="4" valign="middle" /> [golang / **crypto**](https://github.com/golang/crypto)
-:star: 2416
+:star: 2.4k
 > [mirror] Go supplementary cryptography libraries
 
 <img src="https://images.weserv.nl?fit=cover&h=24&mask=circle&maxage=7d&url=https%3A%2F%2Fgithub.com%2Fklauspost.png&w=24" width="24" height="24" hspace="4" valign="middle" /> [klauspost / **reedsolomon**](https://github.com/klauspost/reedsolomon)
-:star: 1444
+:star: 1.4k
 > Reed-Solomon Erasure Coding in Go
 
 <img src="https://images.weserv.nl?fit=cover&h=24&mask=circle&maxage=7d&url=https%3A%2F%2Fgithub.com%2Fsegmentio.png&w=24" width="24" height="24" hspace="4" valign="middle" /> [segmentio / **asm**](https://github.com/segmentio/asm)

internal/cmd/docgen/main.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"log"
+	"math"
 	"net/url"
 	"os"
 	"regexp"
@@ -45,6 +46,7 @@ func mainerr() (err error) {
 		"include": include,
 		"snippet": snippet,
 		"avatar":  avatar,
+		"stars":   stars,
 	})
 
 	// Load template.
@@ -191,3 +193,12 @@ func avatar(owner string, size int) (string, error) {
 	format := `<img src="%s" width="%d" height="%d" hspace="4" valign="middle" />`
 	return fmt.Sprintf(format, src.String(), size, size), nil
 }
+
+// stars formats a Github star count, rounding to thousands in the same style as Github.
+func stars(n int) string {
+	if n < 1000 {
+		return strconv.Itoa(n)
+	}
+	k := math.Round(float64(n)/100.0) / 10.0
+	return strconv.FormatFloat(k, 'f', -1, 64) + "k"
+}

internal/cmd/docgen/templates/readme.tmpl

@@ -108,7 +108,7 @@ Popular projects using `avo`:
 {{ range .Projects.Top 10 -}}
 {{ if lt .Metadata.Stars 100 }}{{break}}{{ end -}}
 {{ avatar .Repository.Owner 24 }} [{{ .Repository.Owner }} / **{{ .Repository.Name }}**]({{ .Repository.URL }})
-:star: {{ .Metadata.Stars }}
+:star: {{ stars .Metadata.Stars }}
 > {{ .Metadata.Description }}
 
 {{ end -}}