doc: do not use tilde for "about" or "approximately"

Refs: https://docs.microsoft.com/en-us/style-guide/a-z-word-list-term-collections/term-collections/special-characters

Author: Trott

doc/api/buffer.md

@@ -5031,9 +5031,10 @@ changes:
 
 * {integer} The largest size allowed for a single `Buffer` instance.
 
-On 32-bit architectures, this value currently is 2<sup>30</sup> - 1 (~1 GB).
+On 32-bit architectures, this value currently is 2<sup>30</sup> - 1 (about 1
+GB).
 
-On 64-bit architectures, this value currently is 2<sup>32</sup> (~4 GB).
+On 64-bit architectures, this value currently is 2<sup>32</sup> (about 4 GB).
 
 It reflects [`v8::TypedArray::kMaxLength`][] under the hood.
 

doc/guides/investigating_native_memory_leak.md

@@ -100,8 +100,8 @@ Leaks can be introduced in native addons and the following is a simple
 example leak based on the "Hello world" addon from
 [node-addon-examples](https://github.com/nodejs/node-addon-examples).
 
-In this example, a loop which allocates ~1 MB of memory and never frees it
-has been added:
+In this example, a loop which allocates approximately 1 MB of memory and never
+frees it has been added:
 
 ```cpp
 void* malloc_holder = nullptr;