Add deps cleanext and DB compression infos

Author: Jean-Lessa

bdk-implementation/database.md

@@ -8,7 +8,7 @@ BDK validators use an in-disk database for storing data about themselves and oth
 
 The database itself is an abstraction of a [Speedb](https://github.com/speedb-io/speedb) database - a simple key/value database, but handled in a different way: keys use *prefixes*, which makes it possible to batch read and write, so we can get around the "simple key/value" limitation and divide data into sectors.
 
-The database requires a filesystem path to open it (if it already exists) or create it on the spot (if it doesn't exist) during construction. It closes itself automatically on destruction.
+The database requires a filesystem path to open it (if it already exists) or create it on the spot (if it doesn't exist) during construction. It closes itself automatically on destruction. Optionally, it also accepts a bool for enabling compression (disabled by default), if needed.
 
 Content in the database is stored as raw bytes. This is due to space optimizations, as one raw byte equals two UTF-8 characters (e.g. an address like `0x1234567890123456789012345678901234567890`, ignoring the "0x" prefix, occupies 20 raw bytes - "12 34 56 ..." - , but 40 bytes if converted to a string, since each byte becomes two separate characters - "1 2 3 4 5 6 ...").
 

understanding-contracts/setting-up-the-development-environment.md

@@ -122,7 +122,7 @@ The versions of those dependencies should suffice out-of-the-box for at least th
 
 #### Tips for dependencies
 
-There is a script called `scripts/deps.sh` which you can use to check if you have those dependencies installed (`deps.sh --check`), and install them in case you don't (`deps.sh --install`). The script expects dependencies to be installed either on `/usr` or `/usr/local`, giving preference to the latter if it finds anything there (so you can use a higher version of a dependency while still keeping your distro's default one).
+There is a script called `scripts/deps.sh` which you can use to check if you have those dependencies installed (`deps.sh --check`), install them in case you don't (`deps.sh --install`), and clean up the external ones for reinstalling (`deps.sh --cleanext`). The script expects dependencies to be installed either on `/usr` or `/usr/local`, giving preference to the latter if it finds anything there (so you can use a higher version of a dependency while still keeping your distro's default one).
 
 **Please note that installing most dependencies through the script only works on APT-based distros** (Debian, Ubuntu and derivatives) - you can still check the dependencies on any distro and install the few ones labeled as "external" (those are fetched through `git`), but if you're on a distro with another package manager and/or a distro older than one of the minimum ones listed above, you're on your own.