top: Replace upip with mip everywhere.

Updates all README.md and docs, and manifests to `require("mip")`.

Also extend and improve the documentation on freezing and packaging.

This work was funded through GitHub Sponsors.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

ports/esp8266/README.md

@@ -200,20 +200,22 @@ Python prompt over WiFi, connecting through a browser.
 - GitHub repository https://github.com/micropython/webrepl.
   Please follow the instructions there.
 
-__upip__
+__mip__
 
-The ESP8266 port comes with builtin `upip` package manager, which can
-be used to install additional modules (see the main README for more
-information):
+The ESP8266 port comes with the built-in `mip` package manager, which can
+be used to install additional modules:
 
 ```
->>> import upip
->>> upip.install("micropython-pystone_lowmem")
+>>> import mip
+>>> mip.install("hmac")
 [...]
->>> import pystone_lowmem
->>> pystone_lowmem.main()
+>>> import hmac
+>>> hmac.new(b"1234567890", msg="hello world").hexdigest()
 ```
 
+See [Package management](https://docs.micropython.org/en/latest/reference/packages.html) for more
+information about `mip`.
+
 Downloading and installing packages may requite a lot of free memory,
 if you get an error, retry immediately after the hard reset.
 

ports/esp8266/boards/manifest.py

@@ -1,9 +1,8 @@
 freeze("$(PORT_DIR)/modules")
-module("upip.py", base_path="$(MPY_DIR)/tools", opt=3)
-module("upip_utarfile.py", base_path="$(MPY_DIR)/tools", opt=3)
-require("ntptime")
 require("dht")
-require("onewire")
 require("ds18x20")
+require("mip")
 require("neopixel")
+require("ntptime")
+require("onewire")
 require("webrepl")