feat(template): add the template

lettre.typ

@@ -0,0 +1,54 @@
+#let lettre(
+  de: "",
+  pour: "",
+  objet: "",
+  date: "",
+  lieu: "",
+  introduction: "",
+  cloture: "",
+  signature: "",
+  post: "",
+  doc
+) = {
+  set page(margin: 1.5in)
+  set par(leading: 0.55em, first-line-indent: 2em, justify: true, spacing: 0.55em)
+  set text(font: "Libertinus Serif", size: 12pt)
+  set document(title: objet, author: signature)
+  show raw: set text(font: "Inconsolata")
+  show heading: set block(above: 1.4em, below: 1em)
+
+  grid(
+    columns: (2fr, 1fr, 2fr),
+    par(de),
+    text[],
+    text[
+      #lieu
+      #if date.trim().len() != 0 [, le #date ]
+    ] + v(2em),
+    text[],
+    text[],
+    par(pour)
+  )
+  v(1em)
+  if objet.trim().len() > 0 {
+    heading(level: 3, text("Objet: " + objet))
+    v(1em)
+  }
+  par(first-line-indent: 0pt, text(introduction + ","))
+  v(1em)
+  doc
+  v(1em)
+  par(first-line-indent: 0pt, text(cloture))
+  v(.7em)
+  grid(
+    columns: (2fr, 1fr),
+    text[],
+    text(signature)
+  )
+  v(1em)
+  post
+}
+
+#let er = [#super[er]]
+#let ème = [#super[ème]]
+#let no(num) = { text([n°~] + num) }