multi: Fix grammatical errors and typos in various docs

docs/INSTALL.md

@@ -21,7 +21,7 @@
 - [Macaroons](#macaroons)
 - [Network Reachability](#network-reachability)
 - [Simnet vs. Testnet Development](#simnet-vs-testnet-development)
-- [Creating a lnd.conf (Optional)](#creating-an-lndconf-optional)
+- [Creating an lnd.conf (Optional)](#creating-an-lndconf-optional)
 
 # Installation
 
@@ -136,7 +136,7 @@ the following commands for your OS:
 <details>
   <summary>macOS</summary>
 
-  First, install [Homebrew](https://brew.sh) if you don’t already have it.
+  First, install [Homebrew](https://brew.sh) if you don't already have it.
 
   Then
 
@@ -590,11 +590,11 @@ password stretching for the wallet encryption and therefore starts up faster
 than a production/mainnet/release build. The binary can be built by running
 `make build-itest`.
 
-# Creating a lnd.conf (Optional)
+# Creating an lnd.conf (Optional)
 
 Optionally, if you'd like to have a persistent configuration between `lnd`
 launches, allowing you to simply type `lnd --bitcoin.testnet --bitcoin.active`
-at the command line, you can create a `lnd.conf`.
+at the command line, you can create an `lnd.conf`.
 
 **On macOS, located at:**
 `/Users/<username>/Library/Application Support/Lnd/lnd.conf`