Remove old docs, rename docs_new to docs

It would be probably good idea to also remove tools/docgen.py and
asciidoc.mk, but asciidoc.mk is still mentioned under `cloud/doc`, which
may contain some useful info which we'll need at least to review before
removing.

PUBLISHED_FROM=faf454d4c52a2f07ea8ac084cf0bd11a0c9c9b3b

docs/c-api/util.h/items.json

@@ -0,0 +1,96 @@
+{
+    "items": [
+        {
+            "type": "markdown",
+            "name": "intro.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_skip.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_ncasecmp.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_casecmp.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_vcmp.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_vcasecmp.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_base64_decode.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_base64_encode.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_stat.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_fopen.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_open.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_start_thread.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_conn_addr_to_str.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_sock_to_str.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_sock_addr_to_str.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_hexdump.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_hexdump_connection.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_avprintf.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_is_big_endian.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_next_comma_list_entry.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_match_prefix.md"
+        },
+        {
+            "type": "markdown",
+            "name": "mg_mk_str.md"
+        },
+        {
+            "type": "markdown",
+            "name": "MG_MK_STR.md"
+        }
+    ]
+}