[TT-9423] Add godoc taskfile (#5303)

https://tyktech.atlassian.net/browse/TT-9423

Run it with task -t `.taskfiles/godoc/Taskfile.yml`, or go into
`.taskfiles/godoc` and run `task`.

Co-authored-by: Tit Petric <tit@tyk.io>
(cherry picked from commit 4def67e)

.taskfiles/godoc/Taskfile.yml

@@ -0,0 +1,19 @@
+---
+version: "3"
+
+tasks:
+  default:
+    desc: "Run godoc on all packages"
+    dir: ../..
+    vars:
+      package:
+        sh: go list .
+      packages:
+        sh: go list ./... | sed -e 's|{{.package}}|.|g'
+    silent: true
+    cmds:
+      - |
+        set -e;
+        {{- range $i, $package := .packages | splitLines -}}
+          go doc {{ $package }}
+        {{ end -}}