Docker Alpine opcache (#2498)

https://github.com/FreshRSS/FreshRSS/pull/2495#discussion_r315662184
https://php.net/ref.opcache
We need to retest the performances
https://github.com/FreshRSS/FreshRSS/pull/2205

Docker/Dockerfile-Alpine

@@ -5,7 +5,7 @@ SHELL ["/bin/ash", "-eo", "pipefail", "-c"]
 RUN apk add --no-cache \
 	apache2 php7-apache2 \
 	php7 php7-curl php7-gmp php7-intl php7-mbstring php7-xml php7-zip \
-	php7-ctype php7-dom php7-fileinfo php7-iconv php7-json php7-session php7-simplexml php7-xmlreader php7-zlib \
+	php7-ctype php7-dom php7-fileinfo php7-iconv php7-json php7-opcache php7-session php7-simplexml php7-xmlreader php7-zlib \
 	php7-pdo_sqlite php7-pdo_mysql php7-pdo_pgsql
 
 RUN mkdir -p /var/www/FreshRSS /run/apache2/

docs/en/admins/02_Installation.md

@@ -8,7 +8,7 @@ You need to verify that your server can run FreshRSS before installing it. If yo
 | ----------- | ---------------- | ----------------------------- |
 | Web server  | **Apache 2**     | Nginx                         |
 | PHP         | **PHP 7+**       | PHP 5.5+                      |
-| PHP modules | Required: libxml, cURL, PDO_MySQL, PCRE and ctype. <br>Required (32-bit only): GMP <br> Recommanded: JSON, Zlib, mbstring, iconv, ZipArchive <br> *For the whole modules list see [Dockerfile](https://github.com/FreshRSS/FreshRSS/blob/744a9e8cf00aef7dec0acfa5f90f0dcfa2ef8837/Docker/Dockerfile-Alpine#L7-L9)* | |
+| PHP modules | Required: libxml, cURL, PDO_MySQL, PCRE and ctype. <br>Required (32-bit only): GMP <br> Recommanded: JSON, Zlib, mbstring, iconv, ZipArchive <br> *For the whole modules list see [Dockerfile](https://github.com/FreshRSS/FreshRSS/blob/master/Docker/Dockerfile-Alpine#L7-L9)* | |
 | Database    | **MySQL 5.5.3+** | SQLite 3.7.4+                 |
 | Browser     | **Firefox**      | Chrome, Opera, Safari, or IE11+ |
 

docs/fr/users/01_Installation.md

@@ -8,7 +8,7 @@ Il est toutefois de votre responsabilité de vérifier que votre hébergement pe
  | --------         | -----------                                                                                                    | ---------------------          |
  | Serveur web      | **Apache 2**                                                                                                   | Nginx                          |
  | PHP              | **PHP 7+**                                                                                                     | PHP 5.5+                       |
- | Modules PHP      | Requis : libxml, cURL, PDO_MySQL, PCRE et ctype<br>Requis (32 bits seulement) : GMP<br>Recommandé : JSON, Zlib, mbstring et iconv, ZipArchive<br>*Pour une liste complète des modules nécessaires voir le [Dockerfile](https://github.com/FreshRSS/FreshRSS/blob/744a9e8cf00aef7dec0acfa5f90f0dcfa2ef8837/Docker/Dockerfile-Alpine#L7-L9)* |                                |
+ | Modules PHP      | Requis : libxml, cURL, PDO_MySQL, PCRE et ctype<br>Requis (32 bits seulement) : GMP<br>Recommandé : JSON, Zlib, mbstring et iconv, ZipArchive<br>*Pour une liste complète des modules nécessaires voir le [Dockerfile](https://github.com/FreshRSS/FreshRSS/blob/master/Docker/Dockerfile-Alpine#L7-L9)* |                                |
  | Base de données  | **MySQL 5.5.3+**                                                                                               | SQLite 3.7.4+                  |
  | Navigateur       | **Firefox**                                                                                                    | Chrome, Opera, Safari, or IE 11+ |