Prose typos in functions, oop_intro and python_oop (found via French edition review)

[mmcky]

Small prose defects in three lectures, found during native-editor review of the French edition (see QuantEcon/lecture-python-programming.fr#77 and QuantEcon/lecture-python-programming.fr#78). All checked at b0b0b56.

functions.md:420 is the one that matters most for the translations: all four editions (fr, zh-cn, fa, ml) copy the bare t. python_oop.md:226 is carried by three. The rest are English-only; the editions already repaired them in translation.

File	Line	Current	Suggested
functions.md	28	"provided by almost all programming."	"…provided by almost all programming languages."
functions.md	38	"2. learn to do is build our own user-defined functions."	"2. learn how to build our own user-defined functions."
functions.md	363	"get rid of the conditionals all together"	"…altogether"
functions.md	420	"computing $x_t$ for some t when"	"…for some $t$ when"
functions.md	672	"Rewrite the function factorial() in from [Exercise 1]"	"…factorial() from [Exercise 1]"
oop_intro.md	195	* e.g.,``imag`` and … (renders "e.g.,imag")	* e.g., `imag` and …
oop_intro.md	302	"add methods to their that measure"	"add methods to their objects that measure"
oop_intro.md	346	"Remember that everything is an object will help you"	"Remembering that everything is an object will help you"
python_oop.md	226	print("Insufficent funds") (line 165 spells it correctly)	print("Insufficient funds")
python_oop.md	158	"Consumer with inital wealth"	"…initial wealth"
python_oop.md	189	"the name of particular person"	"the name of a particular person"
python_oop.md	209	"Here how we set up"	"Here's how we set up"
python_oop.md	243	"the __init_ method"	"the __init__ method"

Timing note for whoever picks this up: these edits trigger translation syncs to all four editions. The French edition's review PRs for functions and oop_intro merged on 2026-09-23, so this can go in now.