Moved instructions [skip ci]

README.md

@@ -18,20 +18,14 @@ make
 make install # may need sudo
 ```
 
-If you have multiple server installations you will want to specify the installation's `PG_CONFIG` path.
-```sh
-...
-export PG_CONFIG=/Applications/Postgres.app/Contents/Versions/latest/bin/pg_config
-make
-make install
-```
-
 Then load it in databases where you want to use it
 
 ```sql
 CREATE EXTENSION vector;
 ```
 
+See the [installation notes](#additional-installation-instructions) if you run into issues
+
 You can also install it with [Docker](#docker), [Homebrew](#homebrew), [PGXN](#pgxn), [Yum](#yum), or [conda-forge](#conda-forge)
 
 ## Getting Started
@@ -349,6 +343,17 @@ avg(vector) → vector | arithmetic mean
 
 ## Additional Installation Instructions
 
+### Multiple Postgres Installations
+
+If your machine has multiple Postgres installations, specify the one to use with:
+
+```sh
+export PG_CONFIG=/Applications/Postgres.app/Contents/Versions/latest/bin/pg_config
+make clean
+make
+make install
+```
+
 ### Ubuntu and Debian
 
 If compilation fails with `fatal error: postgres.h: No such file or directory`, make sure Postgres development files are installed on the server.